3(4+n) = 30 + n 12 + 3n = 30 + n (use the distributive property to eliminate parentheses) 3n = 18 + n (subtract 12 from both sides) 2n = 18 (subtract n from both sides) n = 9 (divide both sides by 2)

##### The number is 9.

__Check__4+ 9 = 13 (4 is added to a number) 13*3 = 39 = 30 + 9 (triple the sum is 30 more than the number)