Question

分解因式:1,9/4x^2+x+1/9 2,4a(2x-y)^2-36a 3,a^2(x^2-y^2)+b^2(y^2-

Answer 1

1,9/4x^2+x+1/9

=(3x/2+1/3)²

2,4a(2x-y)^2-36a

=4a[(2x-y)²-9]

=4a(2x-y+3)(2x-y-3)

3,a^2(x^2-y^2)+b^2(y^2-x^2)

=(x²-y²)(a²-b²)

=(x+y)(x-y)(a+b)(a-b)