solve the system:
-3x-4y=-18
-2x+4y=8
put your answers in ordered pair form: (x,y). show work.
To solve the system of equations:
1) Multiply the second equation by -1 to eliminate the variable y.
-2x + 4y = 8 → -2x - 4y = -8
2) Add the two equations together.
(-3x - 4y) + (-2x - 4y) = (-18) + (-8)
-3x - 4y - 2x - 4y = -26
-5x - 8y = -26
3) Solve the new equation for x.
-5x - 8y = -26 → -5x = -26 + 8y → x = (8y - 26)/-5
4) Substitute this value of x into one of the original equations.
-3(8y - 26)/-5 - 4y = -18
(24y - 78)/5 - 4y = -18
24y - 78 - 20y = -90
4y = -90 + 78
4y = -12
y = -12/4
y = -3
5) Substitute the value of y back into the expression found for x.
x = (8(-3) - 26)/-5
x = (-24 - 26)/-5
x = -50/-5
x = 10
So the solution to the system of equations is (x, y) = (10, -3).