Answer:
(x, y) = (-10, 5)
Step-by-step explanation:
This one can be a little tricky because the variables in the equations are not in the same order. It might help to rewrite the system as ...
- 5x +6y = -20
- 2x +9y = 25
Multiplying the first equation by 3 and subtracting 2 times the second equation can eliminate the y-variable:
3(5x +6y) -2(2x +9y) = 3(-20) -2(25)
11x = -110 . . . . . . simplify
x = -10 . . . . . . . . divide by 11
5(-10) +6y = -20 . . . substitute for x in the first equation
6y = 30 . . . . . . . . add 50
y = 5 . . . . . . . . . . divide by 6
The solution is (x, y) = (-10, 5).
