How do you solve the system of equations 9x - 11y = 25 and y = 4x - 15?

1 Answer
Jan 1, 2018

(4,1)

Explanation:

Since we know that y=4x-15, we can plug that into the first equation. Doing so, we get:

9x-11(4x-15)=25

Doing some algebra:

9x-44x+165=25

-35x=-140

x=4

Now that we know one variable, it's easy to find the other:

y=4(4)-15

y=1