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39 votes
39 votes
Solve the system using substitution.
X = Y-4
2x + 3y = 12

User Aaron Maslen
by
2.9k points

2 Answers

13 votes
13 votes

Answer:

(0, 4 )

Explanation:

Given the 2 equations

x = y - 4 → (1)

2x + 3y = 12 → (2)

Substitute x = y - 4 into (2)

2(y - 4) + 3y = 12 ← distribute and simplify left side

2y - 8 + 3y = 12

5y - 8 = 12 ( add 8 to both sides )

5y = 20 ( divide both sides by 5 )

y = 4

Substitute y = 4 into (1) for corresponding value of x

x = 4 - 4 = 0

solution is (0, 4 )

User Simon Epskamp
by
3.3k points
15 votes
15 votes

Answer:

Explanation:

If you know that x = y - 4, you can plug that value into the equation 2x + 3y = 12 for x. This would look like:

2(y - 4) + 3y = 12

Simplify:

2y - 8 + 3y = 12

5y - 8 = 12

add 8 to both sides

5y = 20

divide both sides by 5

y = 4

Now, substitute y = 4 back into the equation x = y - 4:

x = 4 - 4

and simplify:

x = 0

This means that the answer is x = 0 and y = 4.

User Rakesh Singh
by
3.0k points