Solve the system of equations:
5x-3y=-34
2x+7y=-30

Question

Solve the system of equations: 
5x-3y=-34
2x+7y=-30

anonymous · Answer

Have you learnt the elimination method?

hero · Answer

Multiply the first equation by 2:

10x - 6y = -68
2x + 7y = -30

Combine both equations together:
12x + y = -98

Isolate y:
y = -98 - 12x

substitute the expression for y into the second equation:
2x + 7(-98 - 12x) = -30
2x -686 - 84x = -30

-686 + 30 = 84x - 2x
-656 = 82x
-656/82 = x
-8 = x

hero · Answer

Now you should be able to find y on your own by substituting x = -8 back into one of the original equations.

hero · Answer

@dcortinas, have you figured out the value of y yet?