Question

What is the solution to the system? x + y = 20 32x + 54y = 816 a) (10,10) b) (5, 15) c) (12,8) d) (8,12)

Answer 1

x+ y =20 (a)

32x+54y= 816 (b)

Multiply (a) by 32 and subtract (a) to (b). Then solve for y:

32x+54y= 816

-

32x+32y=640

___________

22y= 176

y= 176 /22

y= 8

Replace y on (a) and solve for x

x+8=20

x=20-8

x=12

Solution:

(x,y) = (12,8) option c