Question

Solve the system of equations:

-3x + 7y = -15
3x + 5y = 15

what do X and Y equal?

Answer 1

x=5

y=0

Explanation:

Let's solve the system of equations through elimination

Solving by elimination is when you add or subtract one equation by the other to eliminate one variable

In this case, adding 3x and -3x would cancel each other out so we should add the equations

`-3x + 7y = -15\\+(3x + 5y = 15)\\0+12y=0\\12y=0`

Now solve for y

Divide both sides by 12 to isolate y

`12y=0\\\\(12y)/(12) =(0)/(12) \\\\y=0`

Now sub in the value of y into one of the original equations and solve for x

`3x+5y=15\\3x+5(0)=15\\3x=15\\`

Divide both sides by 3 to isolate x

`(3x)/(3) =(15)/(3) \\x=5`