Solve for 2x + 4y = 40 and 3x + 4y = 40

2x + 4y = 40

2x + 4y-4y = 40-4y

2x= 40-4y

2x/2= 40-4y/2

x=20-2y

3x + 4y = 40

3(20-2y) + 4y = 40

3(20) (3)(-2y) + 4y = 40

60-6y+ 4y = 40

60-2y= 40

60-2y-60= 40-60

-2y=-20

-2y/-2=-20/-2

y=10

x=20-2y

x=20-2(10)

x=20-20=0