Question

Solve the system of equations 2x + 3y = 40 and –2x + 2y = 20. A. x = –10, y = 20 B. x = 2, y = 12 C. x = –6, y = 4 D. x = 10, y = 20

Answer 1

2x + 3y = 40   ...........(1)

-2x + 2y = 20   .........(2)

(1) + (2)

(2x + 3y) + (-2x + 2y) = 40 + 20

5y = 60

y = 12

if  2x + 3y = 40

2x + 3*12 = 40

2x = 40 - 36 = 4

x = 2

answer is b) x = 2 and y = 12