Question

Solving systems of equation using elimination

1)2x+2y = 8
x – 2y = 4

2)x+y=8
x-y=4

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

4)2x+2y=4
x-y=4

5)x+2y=8
x+3y=4


I need the answer for each problem. Please help is due in 30 minutes!

Answer 1

2x+2y = 8

x – 2y = 4

3x=12

x=12/3=4

x=4

2x+2y=8

2(4) + 2y = 8

8+2y = 8

2y=8-8

2y=0

y=0/2=0

2(4)+2(0)=8

8+0=8

x+y=8

x-y=4

2x=12

x=12/2=6

6+y=8

y=8-6=2

6+2=8

2x+2y=4

x-y=4

2x+2y=4

2(x-y=4)

2x+2y=4

2x-2y=8

4x=12

x=12/4=3

2(3)+2y=4

6+2y=4

2y=4-6

2y=-2

y=-2/2=-1

2(3)+2(-1)=4

6+-2=4

x+2y=8

-(x+3y=4)

x+2y=8

-x-3y=-4

-1y=4

y=4/-1=-4

x+2(-4)=8

x+-8=8

x=8+8=16