Answer:
number is 16
Explanation:
let n be the number then three times the number is 3n and decreased by 9 is
3n - 9
form the equation
3n - 9 = 39 ( add 9 to both sides )
3n - 9 + 9 = 39 + 9 ( simplify both sides )
3n = 48 ( divide both sides by 3 )
n =
, that is
n = 16
the number is 16