Question

If 4x-2y=10 and 7x+2y=23 what is the value of x

Answer 1

4x-2y=10
7x+2y=23

First, we can solve one of the problems in order to come up with an expression to represent y.

-2y=4x+10
y=-2x-5

Now that we have our y value, we can plug it in to the other equation.

7x+2(2x-5)=23
7x+4x-10=23
11x=33
x=3

There's your x value, 3. I am going to solve for y as well just so that you can see how to check your work.

We can plug our x value into the other equation now to find y.

4(3)-2y=10
12-2y=10
-2y=-2
y=1

Would you look at that? We have both the x and y values. Now we can just plug them in to either equation.

7(3)+2(1)=23
21+2=23
23=23

23 indeed equals 23, therefore proving that both variables are correct. There you go!