SOLUTION: Ive been working on a review for a test next tuesday, but i keep getting confused with this type of equation by using substitution.
{2x-y=2
{3x-2y=11
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Question 499795: Ive been working on a review for a test next tuesday, but i keep getting confused with this type of equation by using substitution.
{2x-y=2
{3x-2y=11
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
Start with the given system of equations:
Now in order to solve this system by using substitution, we need to solve (or isolate) one variable. I'm going to solve for y.
So let's isolate y in the first equation
Start with the first equation
Subtract from both sides
Rearrange the equation
Divide both sides by
Break up the fraction
Reduce
---------------------
Since , we can now replace each in the second equation with to solve for
Plug in into the second equation. In other words, replace each with . Notice we've eliminated the variables. So we now have a simple equation with one unknown.
Distribute to
Multiply
Combine like terms on the left side
Subtract 4 from both sides
Combine like terms on the right side
Divide both sides by -1 to isolate x
Divide
-----------------First Answer------------------------------
So the first part of our answer is:
Since we know that we can plug it into the equation (remember we previously solved for in the first equation).
Start with the equation where was previously isolated.
Plug in
Multiply
Combine like terms
-----------------Second Answer------------------------------
So the second part of our answer is:
-----------------Summary------------------------------
So our answers are:
and
which form the point