SOLUTION: Actually, I need help with solving a system by addition/subtraction elimination. For example 2x -3 y=-6 x=7-y. I need an equation the preceeding was just and example. Once I get th

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Question 332515: Actually, I need help with solving a system by addition/subtraction elimination. For example 2x -3 y=-6 x=7-y. I need an equation the preceeding was just and example. Once I get the equation, I need to follow the steps below
Then follow 5 steps

Step 1 I need to write both equations in the form ax+by=c

Step 2 multiply the second equation by 2 in order to make the coefficients of the x terms equal.
Step 3 subtract the second equation from the first equation to eliminate the x variable
Step 4 solve the equation for y
Step 5 select one equation and substitute 4 for y and solvefor x
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
4x+3y= 87>>>>>...1
2x-y= 21>>>>>>...2
..
multiply equation 2 by 2
4x-2y=42
..
(4x+3y)-(4x-2y)=87-42
4x+3y-4x+2y=45
5y=45
divide by 5
5y/5 = 45/5
y=9
..
2x-y=21
plug the value of y in the equation
2x-9=21
add 9
2x-9+9=21+9
2x=30
divide by 2
2x/2 = 30/2
x=15