Six times a number t can be written as: 6*t
Then, the sum of fifteen and six times a number t can be written as: 15 + 6t
Addittionally, this sum is equal to 81, it means that the equation is:
15 + 6t = 81
So, to solve for t, we subtract 15 from both sides of the equation:
15 + 6t - 15 = 81 - 15
6t = 66
Finally, dividing by 6 into both sides, we get:
6t =