Find the value of x examples

Step 1

Write out the two equations that have the two variables you want to solve. For this example, we will find the value for "x" and "y" in the two equations "3x + y = 2" and "x + 5y = 20"

Step 2

Solve for one of the variables in on one of the equations.

For this example, let's solve for "y" in the first equation. Subtract 3x from each side to get "y = 2 – 3x"

Step 3

Plug in the y value found from the first equation in to the second equation in order to find the x value.

Find the value of x and y class 9

In the previous example, this means the second equation becomes "x + 5(2- 3x) = 20"

Step 4

Solve for x. The example equation becomes "x + 10 – 15x = 20," which is then "-14 x + 10 = 20." Subtract 10 from each side, divide by 14 and you have end up with x = -10/14, which simplifies to x = -5/7.

Step 5

Plug in the x value in to the first equation to find out the y value.

y = 2 – 3(-5/7) becomes 2 + 15/7, which is 29/7.

Step 6

Check your work by plugging in the x and y values in to both of the equations.