First, figure out what you do and don't know.... You do know that 3 times the sum of a number and 4 is 18 more than the number....you don't know the number so you make it the variable x now take 3 times the sum of a number and 4 and make that an expression 3x+4 this expression is the same or equal to the sum of x and 18 x+18 3x+4=x+18 2x+4=18 2x=14 x=7 hope this helped :)
