9514 1404 393
Answer:
(x, y) = (40, 11/3)
Explanation:
The variable x can be eliminated by subtracting the first equation from the second.
(x -9y) -(x -12y) = (7) -(-4)
3y = 11 . . . . . . .simpify
y = 11/3 . . . . . .divide by 3
x -9(11/3) = 7 . . . . substitute for y in the second equation
x = 40 . . . . . . . add 33
The solution is (x, y) = (40, 11/3).