Question

сократить дробь
y^2-y
1-y^2

a^2-4
2a-a^2

3x-3c
ac-ax

Answer 1

$frac{y^2-y}{1-y^2} = frac{y(y-1)}{(1-y)(1+y)}= frac{-y(1-y)}{(1-y)(1+y)} = -frac{y}{1+y} \\ frac{a^2-4}{2a-a^2} = frac{(a-2)(a+2)}{a(2-a)} = frac{(a-2)(a+2)}{-a(a-2)} =-frac{a+2}{a} \\ frac{3x-3c}{ac-ax} = frac{3(x-c)}{-a(x-c)} =- frac{3}{a}$