What is x plus y equals 2 and x plus 2y equals -10?

Answer 1

I suppose the full question is:

Given the following system of equations, find the values of x and y.

x+y=2

x+2y=-10

First, you need to isolate the variable y in the equation x+y=2

You do this by subtracting x from both sides of the equation.

x+y-x=2-x

Simplify:

y=2-x

Now you substitute the equation 2-x in the place of y in the equation x + 2y=-10

Like this:

x+2y=-10

x+2(2-x)=-10

Distribute the two:

x+4-2x=-10

Combine like terms:

-x+4=-10

Subtract 4 from both sides:

-x+4-4=-10-4

Simplify:

-x=-14

Divide both sides by negative one to get rid of the negative sign in front of x:

-x/-1=-14/-1

Simplify:

x=14

Plug the value of x (14) into the equation x+y=2:

14+y=2

Subtract 14 from both sides:

14-14+y=2-14

Simplify:

y=-12

Now you are done.

From now on, please pay attention in class.

If you don't even know the basic math skills that this requires then you have no future.