SOLUTION: 3x-4y=-1 11y+2=13x I have to solve this problem using substitution and I don't understand could someone please help me?

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Question 120130: 3x-4y=-1
11y+2=13x
I have to solve this problem using substitution and I don't understand could someone please help me?

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
3x - 4y = -1
11y + 2 = 13x
I have to solve this problem using substitution
:
Let's use the 1st equation for substitution in the 2nd equation:
3x - 4y = -1
:
3x = 4y + 1; Added 4y to both sides
:
x = 4%2F3y + 1%2F3; Divided both sides by 3
:
:
Substitute the above for x in the 2nd equation:
11y + 2 = 13x
:
11y + 2 = 13(4%2F3y + 1%2F3)
:
11y + 2 = 52%2F3 + 13%2F3; multiplied inside the brackets by 13
:
Multiply equation by 3 to get rid of the those annoying denominators
3(11y) + 3(2) = 3*52%2F3y + 3*13%2F3
:
33y + 6 = 52y + 13
:
33y - 52y = 13 - 6
:
-19y = +7
:
y = 7%2F%28-19%29
:
y = -7%2F19
:
Find x
x = 4%2F3y + 1%2F3;
:
Substitute -7%2F19 for y
x = %284%2F3%29%2A%28-7%2F19%29 + 1%2F3;
x = -28%2F57 + 19%2F57;
x = -9%2F57
Reduces to:
x = -3%2F19
:
:
Check solutions in 2nd equation:
11y + 2 = 13x
11(-7%2F19) + 2 = 13(-3%2F19)
-77%2F19 + 2 = -39%2F19
-77%2F19 + 38%2F19 = -39%2F19 confirms our solutions
:
This was nasty problem with a lot of steps and fractions;
but each step by itself, is a simple operation; try following it step-by-step.
Let me know how you do.