SOLUTION: slove the system by the addition method x+4y=5 2x+3y=0

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Question 243294: slove the system by the addition method
x+4y=5
2x+3y=0
Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
slove the system by the addition method
system%28x%2B4y=5%2C2x%2B3y=0%29

To make the y's cancel, multiply both sides of the first equation
by -3 and both sides of the second equation by 4

system%28-3%28x%2B4y%29=-3%285%29%2C4%282x%2B3y%29=4%280%29%29

Simplify:

system%28-3x-12y=-15%2C%22%22%2B8x%2B12y=0%29

Add the equations term by term and the y terms cancel
out:

5x=-15

x=-3

Start over:

system%28x%2B4y=5%2C2x%2B3y=0%29

To make the x's cancel, multiply both sides of the first equation
by -2 and leave the second equation as it is:

system%28-2%28x%2B4y%29=-2%285%29%2C2x%2B3y=0%29

Simplify:

system%28-2x-8y=-10%2C%22%22%2B2x%2B3y=0%29

Add the equations term by term and the x terms cancel out:

-5y=-10

y=2

Edwin