Question

-2x-y=-14 and 3x-y=11 by substitution

Answer 1

Solve one equation and subsitute it into the other one.

Answer 2

Which one do you want to solve?

Answer 3

- 2x - y = - 14
3x - y = 11 ---> - y = - 3x + 11 ---> (-1)-y = - 3x + 11 ---> y = 3x - 11 (I multiplied this by a (-1) to make the y positive)

Now we know that y = 3x - 11 and we can substitute it into the 1st equation..

-2x - y = - 14
-2x - (3x - 11) = - 14
- 2x - 3x + 11 = - 14
- 5x + 11 = - 14
- 5x = - 14 - 11
- 5x = - 25
x = 5

now substitute 5 for x into 2nd equation...
y = 3x - 11
y = 3(5) - 11
y = 15 - 11
y = 4

now that we know x = 5 and y = 4 we can check by using any one of the equations....

-2x - y = - 14
-2(5) - 4 = - 14
- 10 - 4 = - 14
- 14 = - 14 (correct)

3x - y = 11
3(5) - 4 = 11
15 - 4 = 11
11 = 11 (correct)

ANSWER : x = 5 and y = 4