Question

помогите.плиз.$frac{y+a}{ b^{2}+ab } + frac{y-b}{ a^{2}+ab }$

Answer 1

$frac{y+a}{b^2+ab} + frac{y-b}{a^2+ab} = frac{y+a}{b(a+b)} + frac{y-b}{a(a+b)} = frac{a(y+a)+b(y-b)}{ab(a+b)} =\\= frac{ay+a^2+by-b^2}{ab(a+b)} = frac{y(a+b)+(a-b)(a+b)}{ab(a+b)} = frac{(a+b )(y+a-b)}{ab(a+b)} = frac{y+a-b}{ab}$