Помогите пожалуйста​

a² - b² = (a - b)(a + b)

(x + √5)/(x² - 5) = (x + √5)/(x - √5)(x + √5) = 1/(x - √5)

(a - y)/(√a + √y) = (√a + √y)(√a - √y)/(√a + √y) = √a - √y

(7 + √7)/√7 = √7(√7 + 1)/√7 = √7 + 1

(c² - 2)/(c - √2) = (c - √2)(c + √2)/(c - √2) = c + √2