5t + (t - 3) - [(7t + 5) - (8 - 3t)] {Rewrite the problem}
5t + 1(t - 3) - [1(7t + 5) - 1(8 + -3t) {Distributive property}
5t + 1t + (-3) - [7t + 5 + (-8) + 3t {Add the opposite}
5t + 1t + (-3) - [10t + (-3)] {Add like terms}
5t + 1t + (-3) - 10t + (-3) {Follow order of operations to add alike terms}
6t - 10t + (-6) {simplify}
-4t + -6 is the simplified form of this problem
I hope this helped :)