Question

数学初二因式分解

25(x+y)的2次方-9(x-y)的2次方

Answer 1

25(x+y)²-9(x-y)²
=[5(x+y)+3(x-y)][5(x+y)-3(x-y)]
=(5x+5y+3x-3y)(5x+5y-3x+3y)
=(8x+2y)(2x+8y)
=4(4x+y)(x+4y)

Answer 2

25（x+y）²-9（x-y）²=｛5（x+y）+3（x-y）｝｛5（x+y）-3（x-y）｝=（8x+2y）（2x+8y）=4（4x+y）（x+4y）

Answer 3

4(4x+y)(x+4y)