专题2-2 用直接开平方法求解一元二次方程-重难点题型(举一反三)(北师大版)

22222222222222专题2.2

用直接开方法求解一二次方程-难点题【师版【识1直开方解一二方】根平根意直开方解元次程方，做接开方.直降解元次程步:①方化

的式②接平化两一一方；解个元次程到原程解【型1直开方解元次程条】20200AB0m0Dm0xmxmm0m0D120201m+1mA1C

B1Dm0+1xmm

222222224222222222222224222222xxm+10xpnx+pp01-202043m+3m4m+3+30m3m31-2020x14m11m242x2x411m10112x214m12mm1＝1x1112x20xpnx+pp0【型2解如

𝟐

的方】

22222222122222122222222222222122222122222220201x2425x9xx324250425

4

5x2-20204x131244x25

4

√45

52

2-202018+162xx116x

11

18+16x2xx

1

22222222222222222222222222222214a0100a2

b0abcac

a122-2020xx11ax1x11axa1ax211√

2𝑎1

√𝑎𝑎

√𝑎𝑎

【型3解如

的方】4x362x136092x13x2113-2020（+26021y2y+212

222224122222222222222224122222222222y+2y2y23-2020y1xp+＝pp0+231y3y1y+2y131yxa0100a2

b0abcac

a1233-20214+12x2+381+3812x+399x+312xpnx+pp0【型4已方的求母值20202xc0x2c244

222222212322223𝑎3𝑎2222222212322223𝑎3𝑎240x2224-2020ax1﹣ax2a2ax116016021453aa52114-2020xam22mam33xm=𝑎

√

axmxm1a412

2𝑏22𝑎221212121222222222121212122222222𝑏22𝑎221212121222222222121212122222224-2020axab0mm4𝑎𝑏

mm40+12xm4𝑎1𝑏414【型5已方的求一方的】2020+b01221+m+2+0Ax2x1Cx0x

BxxDxx2m+01x2mb0ax+0ax+m+2b0a++b0x221x+2+b0345-2021x++0x2x2amb0+1Axx2Bxx0x3xDx3x0xb0m1

+xax+m+0xx11+1211xm+1b0a+1+b0

2222222112121221𝑏22𝑎22222222222112121221𝑏22𝑎2222am012xaa0xm1b0121120D5-2020x++0x3xabm2+m

+b0ax+1+b0x+1+13+1a2+m+02+1xa+mb0x3x22x+132x12x2x2x2x5-xmaa0x3x2

2

𝑏m𝑎++b01322𝑏2𝑏𝑏𝑎

2

b0

12

2

b04547x

22nn4331212223222222222222222222nn4331212223222222222222222273x𝑏m𝑎【型6直开方解定问】2020xynxyxy4yx18A1x2Cx3x3

Bx6xD1x2x18x18xy3y318x26-2020pqm12minx1x1xx1xx1x11x1xminx1xx1√6-2020ababba+3abb

2222222222222222222222222222222222222222222222222222222222222222a3b129636421xx30x2x+65xx40x230x302x5+2+3x103+6x+33x+65x+2+335xx

x230xx2303323x5xxx8160xx5xx+3xx5x+2xx53x+3xx5+3x69xx1462020x4x+4x+4+4]4x+444

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