第2章 有理数的运算【章末复习】 课件-2026-2027学年人教版数学七年级上册

#人教版七年级上册数学第2章《有理数的运算》章末复习专项练习##一、知识梳理###1.有理数加法1.同号两数相加：取相同符号\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)并把绝对值相加。2.异号两数相加\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)绝对值不等：取绝对值较大的数的符号\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)并用大绝对值减去小绝对值。3.互为相反数的两数相加得$\boldsymbol{\(\boldsymbol{0}\)}$\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)一个数同\(\boldsymbol{0}\)相加\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)仍得这个数。加法运算律：加法交换律：$\(a+b=b+a\)$加法结合律：$\((a+b)+c=a+(b+c)\)$###2.有理数减法减去一个数\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)等于加上这个数的相反数：$\boldsymbol{a-b=a+(-b)}$###3.有理数乘法两数相乘\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)同号得正\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)异号得负\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)绝对值相乘\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)任何数乘\(\boldsymbol{0}\)都得\(\boldsymbol{0}\)。多个非\(\boldsymbol{0}\)数相乘：负因数个数为偶数\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)积为正\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)负因数个数奇数\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)积为负。乘法运算律：交换律$\(ab=ba\)$\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)结合律$\((ab)c=a(bc)\)$\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)分配律$\(a(b+c)=ab+ac\)$###4.有理数除法除以一个不等于\(\boldsymbol{0}\)的数\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)等于乘这个数的倒数：$\boldsymbol{a\divb=a\cdot\dfrac1b(b\neq\(\boldsymbol{0}\))}$两数相除\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)同号得正\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)异号得负\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)并把绝对值相除\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)\(\boldsymbol{0}\)除以任何不为\(\boldsymbol{0}\)的数都得\(\boldsymbol{0}\)。###5.有理数乘方$a^n$：$n$个$a$相乘\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)$a$是底数\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)$n$是指数。负数的奇次幂是负数\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)负数的偶次幂是正数\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)正数任何次幂都是正数\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)$\(\boldsymbol{0}\)$的正整数次幂是$\(\boldsymbol{0}\)$。⚠️$(-a)^n$与$-a^n$不一样：$(-3)^2=9\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)-3^2=-9$###6.混合运算顺序1.先**乘方**\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)再乘除\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)最后加减\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)2.同级运算\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)从左向右\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)3.有括号\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)先算括号内（小括号→中括号→大括号）。>易错提醒1.\(\boldsymbol{0}\)没有倒数\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)2.符号是计算最容易出错地方\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)3.$-1$的奇次幂$=-1$\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)$-1$偶次幂$\(=1\)$\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)4.分配律去括号\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)括号内每一项都要相乘\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)不要漏乘。##二、基础巩固（填空题）1.$(-5)+(-3)=$____\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)$(-5)\(+3\)=$____。2.$(-7)-(-2)=$____\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)$4-7=$____。3.$(-4)\times(-6)=$____\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)$(-2)\times3=$____。4.$(-12)\div(-3)=$____\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)$(-18)\div6=$____。5.$(-2)^3=$____\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)$-2^3=$____\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)$(-1)^{2\(\boldsymbol{0}\)26}=$____。6.$-\dfrac23$的倒数是____。##三、判断题（对打√\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)错打×）1.两个数相加\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)和一定大于任意一个加数。（）2.减去一个负数\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)等于加上它的相反数。（）3.几个有理数相乘\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)只要有一个因数为\(\boldsymbol{0}\)\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)积就是\(\boldsymbol{0}\)。（）4.$(-3)^2=-9$。（）5.\(\boldsymbol{0}\)除以任意一个数\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)结果都是\(\boldsymbol{0}\)。（）6.乘法分配律$\(a(b+c)=ab+ac\)$。（）##四、选择题1.$-3+5$结果等于（）A.$-8$B.$8$C.$-2$D.$2$2.计算$(-2)\times(-3)$的值为（）A.$-6$B.$6$C.$-5$D.$5$3.下列计算正确的是（）A.$-2^2=4$B.$(-2)^2=4$C.$(-2)^3=8$D.$(-1)^2=-1$4.下列说法正确的是（）A.倒数等于本身的数只有1B.任何数乘$-1$得到它的相反数C.有理数减法就是直接把两数相减D.\(\boldsymbol{0}\)有倒数5.计算$-\(\boldsymbol{24}\)\times\left(\dfrac13-\dfrac14\right)$\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)用分配律结果是（）A.$-2$B.$2$C.$-14$D.$14$##五、计算题1.$-7+12-(-9)$2.$(-18)\div2\times\left(-\dfrac13\right)$3.$-2^2+|5-8|\(+2\)4\div(-3)\times\dfrac13$4.$\left(-\dfrac12+\dfrac23-\dfrac56\right)\times(-12)$##六、解答题1.简述有理数混合运算顺序。2.已知$a=-3,b=2,c=-4$\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)求代数式$a-bc$的值。3.冷库初始温度$-4^\circ\text{C}$\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)每小时降温$3^\circ\text{C}$\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)连续降温5小时\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)求5小时后冷库温度。##七、能力提升1.已知$|x\(+2\)|+(y-3)^2=\(\boldsymbol{0}\)$\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)求$(x+y)^{2\(\boldsymbol{0}\)26}$的值。2.某股民上周星期五收盘持有股票1\(\boldsymbol{0}\)\(\boldsymbol{0}\)\(\boldsymbol{0}\)股\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)每股2\(\boldsymbol{0}\)元\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)本周涨跌：周一$\(+2\)$\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)周二$-1$\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)周三$\(+3\)$\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)周四$-2.5$\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)周五$-1.5$（单位：元）。（1）周五收盘每股多少元？（2）本周内每股最高价是多少？##八、参考答案###一、基础巩固1.$-8\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)-2$2.$-5\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)-3$3.$\(\boldsymbol{24}\)\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)-6$4.$4\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)-3$5.$-8\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)-8\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)1$6.$-\dfrac32$###二、判断题1.×2.√3.√4.×5.×（\(\boldsymbol{0}\)不能除以\(\boldsymbol{0}\)）6.√###三、选择题1.D2.B3.B4.B5.B###五、计算题1.$$\begin{align*}-7+12-(-9)&=-7+12+9\\&\(=1\)4\end{align*}$$2.$$\begin{align*}(-18)\div2\times\left(-\dfrac13\right)&=-9\times\left(-\dfrac13\right)\\&=3\end{align*}$$3.$$\begin{align*}-2^2+|5-8|\(+2\)4\div(-3)\times\dfrac13&=-4\(+3\)+(-8)\times\dfrac13\\&=-1-\dfrac83\\&=-\dfrac{11}{3}\end{align*}$$4.$$\begin{align*}\left(-\dfrac12+\dfrac23-\dfrac56\right)\times(-12)&=-\dfrac12\times(-12)+\dfrac23\times(-12)-\dfrac56\times(-12)\\&=6-8+1\(\boldsymbol{0}\)\\&=8\end{align*}$$###六、解答题1.先乘方\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)再乘除\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)最后加减\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)同级运算从左向右\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)有括号\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)先算括号内部。2.解：$$\begin{align*}a-bc&=-3-(2)\times(-4)\\&=-3-(-8)\\&=-3+8\\&=5\end{align*}$$答：结果为$5$。3.解：$-4+(-3)\times5=-4-15=-19^\circ\text{C}$答：5小时后温度$-19^\circ\text{C}$。###七、能力提升1.解：$\because|x\(+2\)|\ge\(\boldsymbol{0}\)\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)(y-3)^2\ge\(\boldsymbol{0}\)$\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)两个非负数相加等于\(\boldsymbol{0}\)$\thereforex\(+2\)=\(\boldsymbol{0}\)\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)y-3=\(\boldsymbol{0}\)$\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)$x=-2\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)y=3$$(x+y)^{2\(\boldsymbol{0}\)26}=(-2\(+3\))^{2\(\boldsymbol{0}\)26}\(=1\)^{2\(\boldsymbol{0}\)26}\(=1\)$答：结果是$1$。2.（1）$2\(\boldsymbol{0}\)\(+2\)-1\(+3\)-2.5-1.5=2\(\boldsymbol{0}\)$（元）（2）周一：$22$\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)周二：$21$\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)周三：$\(\boldsymbol{24}\)$\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)周四：$\(21.5\)$\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)周五：$2\(\boldsymbol{0}\)$最高价$\boldsymbol{\(\boldsymbol{24}\)}$元。答：（1）周五收盘每股2\(\boldsymbol{0}\)元\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)（2）本周最高每股\(\boldsymbol{24}\)元。##九、易错总结1.乘方重点区分：$-a^2$底数是$a$\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)$(-a)^2$底数是$-a$\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)2.乘除同级运算\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)**必须从左往右算**\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)不能随便改变顺序\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)3.分配律一定要给括号里**每一项**相乘\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)不要漏项\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)4.绝对值、平方具有非负性：$|A|\ge\(\boldsymbol{0}\)\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)A^2\ge\(\boldsymbol{0}\)$\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)两个非负数相加等于\(\boldsymbol{0}\)\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)则各自等于\(\boldsymbol{0}\)\(-8\(-5\(\(\boldsymbol{24}\)\(4；-3\)-6\)-3\)-2\)5.应用题注意正负号含义\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)股票涨跌是在**前一天收盘价**基础上变化。下一节：**第3章代数式章末复习**\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge0，A^2\ge0\)y=3\)y-3=0\)(y-3)^2\ge0\)-3^2=-9\)继续同模板出题吗？>本回答由AI生成\((-3)^2=9\(\because|x+2|\ge0\(\thereforex+2=0\(x=-2\(|A|\ge