You didn't write the equation you like to be solved. It is clear though, from the options you gave, that there are two equations you want to be solved simultaneously. I will give an example to illustrate this, and you may apply the process in solving your problem.
Explanation:
Let
x + y = 7 ....................................(1)
x - 2y = -2...................................(2)
SOLVING USING THE SUBSTITUTION METHOD.
From (1), make y the subject.
y = 7 - x ....................................(3)
Substitute the value of y in (3) into (2)
x - 2(7 - x) = -2
x - 14 + 2x = -2
x + 2x = -2 + 14
3x = 12
Divide both sides by 3
x = 12/3 = 4
Now use x = 4 in (3)
y = 7 - 4 = 3
Therefore, ( x, y) = (4, 3)
SOLVING USING THE ELIMINATION METHOD.
x + y = 7 ....................................(1)
x - 2y = -2...................................(2)
First, let us eliminate x by subtracting (2) from (1)
(x + y) - (x - 2y) = 7 - (-2)
y + 2y = 7 + 2
3y = 9
Divide both sides by 3
y = 9/3 = 3
To eliminate y, first multiply (1) by 2, and add the result to (1)
2 × (1): 2x + 2y = 14 ........................(3)
................x - 2y = -2.........................(2)
____________________
...............3x = 12
............... x = 12/3 = 4
Therefore (x, y) = (4, 3)