How do you solve "Twelve less than the product of three and a number is less than 21" and graph the solution on a number line?

1 Answer
Jun 17, 2017

Answer:

#x < 11#

Explanation:

Translate the english into maths, one phrase at a time:

Let the number be#x#

Thee product of #3# and a number#" "rarr" " 3xx x = 3x#

#12 "less than the product " rarr" " 3x-12#

#"is less than "21" "rarr" " 3x-12 <21#

Solve for x

#3x-12 < 21#

#3x < 21+12#

#3x < 33#

#x < 11#

On a number line graph there will be an open circle on #11# because it is not part of the solution, and a line to infinity to the left.