# If the sum of a number and three is tripled, the result is nine less than twice the number, how do you find the number?

##### 1 Answer

Oct 16, 2015

#### Answer:

#### Explanation:

Let's call

You know that if you **triple** the sum of **less** than **twice** the number

This means that you can write

#underbrace((x +3) * 3)_(color(blue)("three times the sum of x and 3")) = overbrace(2 * x - 9)^(color(red)("9 less than twice the value of x"))#

Rearrange the above equation to solve for

#3x + 9 = 2x - 9#

#3x - 2x = -9 - 9#

#x = color(green)(-18)#