Question

(y-2)(y+3)-(y-1)2+(5-y)(y+5)

Answer 1

(y-2)(y+3)-(y-1)^2+(5-y)(y+5)=y^2+y-6-y^2+2y-1+25-y^2=-y^2+3y+18=-(y^2-3y-18)=-(y-6)(y+3)=(6-y)(y+3)

Answer 2

Решение:

(y-2)(y+3)-(y-1)²+(5-y)(y+5)=

y²+3y-2y-6-(y²-2y+1)+5y+25-y²-5y=y²+y-6-y²+2y-1+25-y²=-(y²-3y-18)=(6-y)(y+3)