Question

Which system of equations is equivalent to the system of equations shown?

x - 2y = 4
3x + y = 9




A) 4x + y = 13 and 2x + 4y = -8
B) 4x - y = 13 and 2x + 4y = 8
C) 4x + y = 13 and 2x - 4y = -8
D) 4x - y = 13 and 2x - 4y = 8

Answer 1

x+y= 4 (-2)
3x+2y = 9

-2x -2y = -8
3x +2y = 9
x = 1

1+y =9
y = 9-1
y =8

Answer 2

x - 2y = 4
3x + y = 9

is equivalent to :
4x - y = 13
2x - 4y = 8