Question 331756: Please show me how to use substitution to solve the system of equations;
5x+5y=-30 and 2x-y=15. Thank you Found 2 solutions by Alan3354, mananth:Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website! Please show me how to use substitution to solve the system of equations;
5x+5y=-30 and 2x-y=15
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5x+5y=-30 --> x+y = -6 reduce whenever possible
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2x-y=15
Solve for y
y = 2x - 15
Sub for y into the 1st eqn
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x+y = -6
x + (2x-15) = -6
Solve for x.
Then sub the number for x and solve for y
You can put this solution on YOUR website! 5x+5y=-30
divide by 5
x+y=-6
y= -6-x
..
and 2x-y=15
plug the value of y in the equation
2x-(-6-x)=15
2x+6+x=15
3x+6=15
3x=15-6
3x=9
x=3
..
plug value of x in the equation x+y=-6
3+y=-6
y=-6-3
y=-9
