Eighty, decreased by three times a number, is the same as five times the
number, increased by eight. Find the
number.

The number is 9.

Step-by-step explanation:

Lets write this as an equation first. We'll substitute the number for the variable x.

80 - 3x = 5x + 8

First, let's add 3x to both sides.

80 - 3x + 3x = 5x + 3x + 8

80 = 8x + 8

Next, let's subtract 8 from both sides.

80 - 8 = 8x + 8 - 8

72 = 8x

Finally, let's divide both sides by 8.

72/8 = 8x/8

9 = x

"x" is 9.

So the secret number is 9.

P.S.

This is my first answer to a question so please don't complain!