Solve the system of equations.



-5x+4y=3

x=2y-15



x equals

y equals

Note: in the 2nd eqn we are given a formula for x: x = 2y-15. Sub this result into the first eqn; doing so will eliminate x:

-5 (2y-15) + 4y = 3

-10y + 75 + 4y = 3, so - 6y = - 72. Then y = 12. Solution is (9,12).

Check this by subst.:

Is - 5 (9) + 4 (12) = 3?

Is - 45 + 48 = 3? YES.