Let x= the number three times a certain number =3xx Subtracted from three times a certain number =3xx−12=3x−12 The result is divided by four =(3x−12)∕4 is means =, hence the answer is 18⇒(3x−12)∕4=18 Now solve for the value of x (3x−12)∕4=18 Multiply both sides by 4 to get rid of the fraction 3x−12=18×4 3x−12=72 3x=72+12 3x=84 Divide both sides by 3 3x∕3=84∕3=28 ⇒x=28