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①9x²-16y²②100-(3x+2y)²③-1+16x²④a²b&

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①9x²-16y²②100-(3x+2y)²③-1+16x²④a²b³-4a²b⑤16x^4-y^4⑥(2x+1)²-x²⑦6.4²-3.6²⑧1.4²×9-2.3²×36⑨x^4-x²
①9x²-16y²②100-(3x+2y)²③-1+16x²④a²b&
(1)
9x²-16y²
=(3x)²-(4y)²
=(3x+4y)(3x-4y)
(2)
100-(3x+2y)²
=10²-(3x+2y)²
=[10+(3x+2y)][10-(3x+2y)]
=(3x+2y+10)(10-3x-2y)
(3)
-1+16x²
=(4x)²-1
=(4x+1)(4x-1)
(4)
a²b³-4a²b
=a²b(b²-4)
=a²b(b+2)(b-2)

16x^4-y^4
=(4x²+y²)(4x²-y²)
=(4x²+y²)(2x+y)(2x-y)

(2x+1)²-x²
=[(2x+1)+x][(2x+1)-x]
=(3x+1)(x+1)

6.4²-3.6²
=(6.4+3.6)(6.4-3.6)
=10x2.8
=28

1.4²×9-2.3²×36
=(1.4x3)²-(2.3x6)²
=4.2²-13.8²
=(4.2+13.8)(4.2-13.8)
=18x(-9.6)
= -172.8

x^4-x²
=(x²+1)(x²-1)
=(x²+1)(x+1)(x-1)
再问: ①xy-9x³y②a³(x+y)²-4a³c²③4a²(x-y)+b²(y-x)④4(a-b)²-(a+b)²⑤(x²+x+1)²-1怎么做 等等采纳
再答: ①xy-9x³y =xy(1-x²) =cy(1+x)(1-x) ②a³(x+y)²-4a³c² =a³[(x+y)²-4c²] =a³[(x+y)+2c][(x+y)-2c] =a³(x+y+2c)(x+y-2c) ③4a²(x-y)+b²(y-x) =4a²(x-y)-b²(x-y) =(x-y)(4a²-b²) =(x-y)(2a+b)(2a-b) ④4(a-b)²-(a+b)² =[2(a-b)+(a+b)][2(a-b)-(a+b)] =(3a-b)(a-3b) ⑤(x²+x+1)²-1 =[(x²+x+1)+1][(x²+x+1)-1] =(x²+x+2)(x²+x) =x(x²+x+2)(x+1)