Question

Show how to use substitution or elimination to solve the following system of equations. Write the solution as an ordered pair.

4x - y = 10
y = 2x - 2

Answer 1

{4, 6}.

Explanation:

4x - y = 10

y = 2x - 2

You can just add these 2 equations and y will be eliminated:

4x - y + y = 2x + 10 - 2

4x = 2x + 8

2x = 8

x = 4

Substitute x = 4 into the first equation:

4(4) - y = 10

y = 16 - 10 = 6.

Answer 2

x=4

y=6

Explanation:

4x - y = 10

y = 2x - 2

4x-(2x-2)=10

4x-2x+2=10

2x+2=10

2x=8

x=4

Subsitute into equation 4x-y=10

16-y=10

y=6