①9x²-16y²②100-(3x+2y)²③-1+16x²④a²b³-4a²b⑤16x^4-y^4⑥(2x+1)²-x²⑦6.4²-3.6
问题描述:
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
答
(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)a...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)