Question

因式分解:1、x的四次方-7x²-18

2、7(a+b)²-5(a+b)-2 3、8x²-26xy+15y² 4、6x²-7x-3 没有财富值了所以还是希望能够有人帮助我 谢谢-3-

Answer 1

x的四次方-7x²-18
=(x^2-9)(x^2+2)
=(x-3)(x+3)(x^2+2)

7(a+b)²-5(a+b)-2

=(7a+7b+2)(a+b-1)

8x²-26xy+15y²

=(4x-3y)(2x-5y)

6x²-7x-3

=（3x+1）(2x-3)

望采纳

Answer 2

x的四次方-7x²-18=(x²-9)(x²+2)=(x-3)(x+3(x²+2)
7(a+b)²-5(a+b)-2 =[7(a+b)+2][(a+b)-1]=(7a+7b+2)(a+b-1)

8x²-26xy+15y²=(4x-3)(2x-5)

6x²-7x-3=(3x+1)(2x-3)

Answer 3

x的四次方-7x²-18
=（x²-9)(x²+2)
=(x+3)(x-3)(x²+2)

7(a+b)²-5(a+b)-2

=[7(a+b)+2][(a+b)-1]
=(7a+7b+2)(a+b-1)

8x²-26xy+15y²

=(2x-5y)(4x-3y)

6x²-7x-3

=(3x+1)(2x-3)