solve these using the elimination method; -5x + 3y = 15, 2x - 3y = -15

Question

 solve that system of linear equations using the elimination method

Answer 1

Our first step is making it so that one of the variables has the same coefficient in both equations. Our y fits the bill and, since the two numbers have different signs, we are going to add them together. This gives us

 

-3x=0

 

Dividing both sides by -3, we find

 

x=0

 

Now that we know the value of x, we can substitute it into one of our equations. Which one doesn't matter, so I will pick the first.

 

-5(0)+3y=15

 

This gives us

 

3y=15

 

Dividing both sides by 3, we find

 

y=3

 

Thus, our answer is

 

x=0  y=3