Question

Solve the system: 5x+6y=−20 9y+2x=25

Answer 1

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).