Question

ax+by/(a-b)(x+y)-bx-ay/(a+b)(x+y)=a^2+b^2/a^2-b^2

Answer 1

1) (а-х)(b+y)+(a-x)(b-y)=2b(a-x)
ab-bx+ay-xy+ab-bx-ay+xy=2ab-2bx
2ab-2bx=2ab-2bx
2) x^2-2x-15=(x-5)(x+3)
x^2-2x-15=x^2-5x+3x-15
x^2-2x-15=x^2-2x-15