We'll use elimination for this system of equations. What variable should get canceled? The x or y? Well to cancel, we need a positive and negative variable.
x + y = 10
x - y = 0
In this case, the y's will cancel out.
Then we will add the x's together and the 10 and 0.
x + y = 10
x - y = 0
Becomes
2x = 10
Now, solve for x. Just simply divide by 2.
2x / 2 = 10 / 2
x = 5
Now we know what the x variable is equal to!
To solve for the y variable, just replace the x variable in one of the equation and solve for y.
I'll use the x + y = 10 equation
We know x is equal to 5.
5 + y = 10
Subtract both sides by 5.
5 - 5 + y = 10 - 5
y = 5
So, both x and y are equal to 5.