SOLUTION: Use the substitution method to solve the following system of equations. And check your answers. (1) 3x

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Question 1019854: Use the substitution method to solve the following system of equations. And check your answers.
(1) 3x - y = 9
(2) 3y + 11 = 5x
Found 2 solutions by Cromlix, ewatrrr:
Answer by Cromlix(4381) (Show Source):
You can put this solution on YOUR website!
Hi there,
(1) 3x - y = 9
(2) 3y + 11 = 5x
Alter equation (1)
3x - y = 9
-y = 9 - 3x
y = 3x - 9
Substitute into Eq.(2)
3y + 11 = 5x
3(3x - 9) + 11 = 5x
9x - 27 + 11 = 5x
collect like terms
9x - 5x = 27 - 11
4x = 16
x = 4
Substitute x = 4 into (1)
3x - y = 9
3(4) - y = 9
12 - y = 9
-y = 9 - 12
-y = -3
y = 3
{4,3}
(1) 3x - y = 9
3(4) - 3 = 9
12 - 3 = 9
9 = 9
(2) 3y + 11 = 5x
3(3) + 11 = 5(4)
9 + 11 = 20
20 = 20
Checked!
Hope this helps :-)

Answer by ewatrrr(24785) (Show Source):
You can put this solution on YOUR website!

Hi
(1) 3x - y = 9
(2) 3y + 11 = 5x
Using the substitution method:
y = 3x-9
3(3x-9) + 11 = 5x
9x - 27 + 11 = 5x
4x = 27-11
4x = 16
x = 4 , y = 3
Checking our Work!

3*3 + 11 = 5*4
20 = 20

SOLUTION: Use the substitution method to solve the following system of equations. And check your answers. (1) 3x - y = 9 (2) 3y + 11 = 5x