Задача 29048 Сократите дробь: а)...

u4614714047

22.07.2018

Сократите дробь: а) (x^2+x-56)/(49-14x+x^2); б) ((2y-3)^2-1)/(y^2+7y-8).

SOVA

22.07.2018

★

x^2+px+q=(x-x_(1))*(x-x_(2))

а) x^2+x-56=(x-7)*(x+8)
x^2-14x+49=(x-7)^2

(x^2+x–56)/(49–14x+x^2)=(x+8)/(x-7)

б)(2y-3)^2-1=(2y-3-1)*(2y-3+1)=(2y-4)(2y-2)=
=2*(y-2)*2*(y-1)=4*(y-2)*(y-1)
y^2+7y-8=(y-1)*(y+8)

((2y–3)^2–1)/(y^2+7y–8)=4*(y-2)/(y+8)