1-a²-4b²+4ab=?

h123w99892022-10-04 11:39:542条回答

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flights0 共回答了24个问题 | 采纳率91.7%: （a+1）^2-(3a^2+4ab+4b^2+2)
=a^2+2a+1-3a^2-4ab-4b^2-2
=-2a^2+2a-1-4ab-4b^2=0
所以2a^2-2a+1+4ab+4b^2=0
(a^2-2a+1)+(a^2+4ab+4b^2)=0
(a-1)^2+(a+2b)^2=0
因为(a-1)^2>=0,(a+2b)^2>=0
所以a-1=0,a+2b=0
a=1,b=-1/2
7月a0; 1年前

分解因式-a²-4b²+4ab= sxcat1年前2: xu_heng2001 共回答了13个问题 | 采纳率61.5%

-a²-4b²+4ab
=-(a²-4ab+4b²)
=-(a-2b)²

1年前查看全部

-a²-4b²+4ab=?(分解因式, -a²-4b²+4ab=?(分解因式, 1.-a²-4b²+4ab=? 2.(x-y)²-10(x-y)+25=? 3.(x²-1)²+6(1-x²)+9=? 4.4(x+y)²-20(x+y)+25=? 5.1/4x²+x+1=? 6.(3x-5y)²+2(3x-5y)+1=? 7.4(2x-y)²+24(2x-y)+36=? 8.(2x-5)²+28x-21=? (分解因式, 小懒猫朵朵1年前2: byymm 共回答了13个问题 | 采纳率100%

1.-a²-4b²+4ab
=-(a^2-4ab+4b^2)
=-(a-2b)^2
2.(x-y)²-10(x-y)+25
=(x-y)^2-2*5(x-y)+5^2
=(x-y-5)^2
3.(x²-1)²+6(1-x²)+9
=(x^2-1)^2-2*3(x^2-1)+3^2
=(x^-1-3)^2
=(x^2-4)^2
=(x+2)^2(x-2)^2
4.4(x+y)²-20(x+y)+25
=[2(x+y)]^2-2*[2(x+y)]*5+5^2
=[2(x+y)-5]^2
=(2x+2y+5)^2
5.1/4x²+x+1
=(x^2+4x+4)/4
=(x+2)^2/2^2
=(x/2+1)^2
6.(3x-5y)²+2(3x-5y)+1
=(3x-5y+1)^2
7.4(2x-y)²+24(2x-y)+36
=[2(2x-y)]^2+2*[2(2x-y)]*6+6^2
=[2(2x-y)+6]^2
=4(2x-y+3)^2
8.(2x-5)²+28x-21
=4x^2-20x+25+28x-21
=4x^2+8x+4
=4(x^2+2x+1)
=4(x+1)^2

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