Упростите выражение

(y-9)^2+(4y-y)(y+6)

(x-4)(x+4)-(x-1)^2

(x-5)^2- (x-7)(x+7)

^-степень

1. (y-9)^2+(4y-y)(y+6) = y^2-18y+81+3y(y+6) = y^2-18y+81+3y^2+18y = 4y^2+81
2. (x-4)(x+4)-(x-1)^2 = x^2-16-(x^2-2x+1) = x^2-16-x^2+2x-1 = -17+2x
3. (x-5)^2-(x-7)(x+7) = x^2-10x+25-(x^2-49) = x^2-10x+25-x^2+49 = -10x+74