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Solving systems of equations by substitution examples 3x + y = 13. 5x -2y = 7.

User Dallonsi
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1 Answer

3 votes

Answer:

x = 3, y = 4

Explanation:

3x + y = 13

5x - 2y = 7

To solve by substitution, you solve one of the equations for a variable, and then plug it into the other equation.

I'm going to choose to solve the first equation for y, as that will be the easiest.

y = -3x + 13 (subtract 3x from both sides)

Now we plug this equation into the y in the second equation and solve for x.

5x - 2(-3x + 13) = 7 (distribute)

5x + 6x - 26 = 7 (combine like terms)

11x - 26 = 7 (add 26 to both sides)

11x = 33

x = 3

Now that we know x is 3, we can plug it in a solve either equation for y.

y = -3(3) + 13

y = -9 + 13

y = 4

User Tyler Streeter
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