SOLUTION: Hi, What are the steps to solve a system of linear equation by using the elimination method? I only know how to use the substitution method. Ex. This one is an example from the

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Question 24895: Hi,
What are the steps to solve a system of linear equation by using the elimination method? I only know how to use the substitution method.
Ex. This one is an example from the text book but I can't really understand.
Please help,
3x - 4y = 1
2x + 3y = 12
Answer by elima(1433) (Show Source):
You can put this solution on YOUR website!
Solving an equation by Elimination means you want to eliminate one of the variables and solve the equation for the other;
3x-4y=1
2x+3y=12
Let's elinate the y;so we need to make -4y and 3y exact opposites of each other;
so we wil multiply the first equation by 3;
(3)3x-4y=1
9x-12y=3 eq(3)
And then muliply the second equation by 4;
(4)2x+3y=12
8x+12y=48(4)
Now wehave two new equations and we add those together;
9x-12y=3
8x+12y=48
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17x =51
When you add those together the y is eliminated and now solve the equation for x;
17x=51
x=3
Now we have an answer for x, so we plug that into oneof the original equations and solve for y;
3(3)-4y=1
9-4y=1
-4y=1-9
-4y=-8
y=
y=2
Hope you understand
=)