Question 342254
7(t-3) = 2(t-9)+2t

7t - 21 = 2t - 18 + 2t

7t - 21 = 4t - 18

7t - 4t = -18 + 21

3t = 3

t = 3/3

t = 1

To check, replace every t with 1 in your original linear equation.
If you get the same answer on both sides, you'll then know that t = 1 is correct.