Question

X + y = 10, x - y = 0 Please solve and explain.

Answer 1

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.