Question

y в квадрате - y : 1 - y в квадрате (Это дробь)

Answer 1

(y^2 - y)/(1-y)= y(y-1)/(1-y)=-y(1-y)/(1-y)= -y

Answer 2

$frac{y^2 - y}{1-y}= yfrac{y-1}{1-y}=-yfrac{1-y}{1-y}= -y$