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?
You know that if you triple the sum of
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)#