Question

Помогите пожалуйста с алгеброй?

Answer 1

$1)\frac{a}{a-b}=\frac{a^{2}}{a^{2}-ab} \\\\2)\frac{x-y}{a}=\frac{x^{2}-y^{2}}{ax+ay} \\\\3)\frac{c+d}{c-d}=\frac{c^{2}-d^{2}}{c^{2}-2cd+d^{2}}\\\\4)\frac{c+a}{a-c}=\frac{a^{2}+2ac+c^{2}}{a^{2}-c^{2}}$