Question

multiplicação polinomios (x-2)(x-3)-(x-y)(x-5)

Answer 1

(x-2).(x-3)
x.x=x²
x.-3=-3x
-2.x=-2x
-2.3=-6

temos 
x²-3x-2x-6
x²-5x-6

(x-y).(x-5)
x.x=x²
x.-5=-5x
-y.x=-yx
-y.-5=5y
x²-5x-yx+5y

x²-5x-6-x²-5x-yx+5y
x²-x²-5x-5x-6-yx+5y
10x-6-yx+5y