Question

Se A = –3 x – 4y + 6 e B = x + y + 1 e C = +3x +2y + 1, então A + B + C é igual a: (A) x – y + 8 (B) 3x + y + 10 (C) – 5x – 3y + 12 (D) – 3x – 5y + 10

Answer 1

A=-3x-4y+6
B=x+y+1
C=3x+2y+1

A+B+C=
(-3x-4y+6)+(x+y+1)+(3x+2y+1)
-3x-4y+6+x+y+1+3x+2y+1

organizando
-3x+x+3x-4y+y+2y+6+1+1=
x-y+8

Alternativa (A)