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

4x-y=10
y=2x-2
*Hint: Substitute 2x-2 for ‘y’ in the first equation: 4x - (2x - 2)= 10

Then solve for ‘x’. Use your answer for 'x' to solve for 'y'.
Please include
The work used to solve for 'x'.
The work used to solve for 'y'.
Your final answer written as an ordered pair (x , y)

User Rastalamm
by
2.4k points

1 Answer

12 votes
12 votes
4x - y = 10
y = 2x - 2

Substitute y (y = 2x - 2) into y for 4x - y = 10:
4x - y = 10
4x - 1(2x - 2) = 10 *the 1 is invisible*
4x - 2x + 2 = 10
- 2 - 2
2x = 8
/2 /2
x = 4

Solving for y:
4x - y = 10
4(4) - y = 10
16 - y = 10
-16 -16
-y = -6
/-1 /-1
y = 6

There is an invisible 1 in front of y.

Final answer (x,y) = (4,6)

Hope that helps!
User Muhammad Hamed
by
3.2k points