Question

1.若M•（x+2/3)=x²-4/9,则M=__ 若（x+2y)•N=x的4次方-1

Answer 1

1.若M•（x+2/3)=x²-4/9=(x+2/3)(x-2/3)

则M=(x-2/3)

若（x+2y)•N=x的4次方-16y的4次方=(x²-4y²)(x²+4y²)=(x-2y)(x+2y)(x²+4y²)

则N=(x-2y)(x²+4y²)

2.若两个正方形的边长之和为17,边长之差为4,

a+b=17,a-b=4

a²-b²=(a+b)(a-b）=68

则大正方形面积减去小正方形面积的差为_68_