### Home > MC1 > Chapter 7 > Lesson 7.2.4 > Problem 7-83

7-83.

Consider the diagram of three pieces of lumber shown below.

If

*x*= 6 meters, how long are all three pieces of lumber laid end to end?

If the total length of all three pieces laid end to end is 20 meters, what is the value of

*x*?

Since *x* = 6 meters, the three pieces of lumber now look like this:

Can you find the total length of the lumber pieces?

Using the diagram above, can you write an expression to represent the pieces of lumber?

If 4 + *x* + *x* = 20, why must *x* + *x* = 16?

Can you find the value of *x*?