Question

Solve the system algebraically.

2x + y - 10 = 0
x - y - 5 = 0

What is the value of y?



-5/3


0


5

Answer 1

2x + y - 10 = 0
x - y - 5 = 0
or you can have it as
2x + y = 10 -----equation 1
x - y = 5 ----equation 2
in this case, you can do elimination method.
since you are to find the value of y. then we would wish to eliminate x
multiplying equation 2 by 2 you'll have:
x - y = 5 x2
2x - 2y = 10 equation 2'
subtract equation 2' from equation 1
2x + y = 10
- 2x - 2y = 10
3y = 0
y=0

Answer 2

Thanks . :)