Question

SOCORRO!! Sabendo que x - y = 5 e a+b = 2, calcule o valor de a.x - a.y + b.x - b.y

Answer 1

$\mathsf{ax-ay+bx-by\to~a(x-y)+b(x-y)}=\\\mathsf{(x-y)(a+b)=5.2=10}$