Question

Pd: Melissa placed red and blue cubes on the table. The sum of red and blue cubes is 8. There are 2 more red cubes than blue cubes. How many blue cubes did Melissa place on the table?

Answer 1

You have the following information:

- The sum of red and blue cubes is 8.

- There are two more red cubes than blue cubes.

In order to determine the number of blue cubes you express the previous situation in an algebraic way.

If x is the number of blue cubes, then (x + 2) is the number of red cubes.

Moreover, if the sum of the cubes is 8, you can write:

x + (x + 2) = 8

solve the previous equation as follow:

x + (x + 2) = 8 eliminate parenthesis

x + x + 2 = 8 subtract 2 both sides

x + x = 8 - 2 simplify like terms

2x = 6 divide by 2 both sides

x = 6/2

x = 3

Hence, there are 3 blue cubes and 3 + 2 = 5 red cubes.