Answer
t=25
Work Step by Step
The distributive property allows us to distribute anything multiplied by something inside of the parenthesis to whatever is inside of the parenthesis. Thus, we distribute the 5 to everything inside of the first set of parenthesis and the 7 to everything inside of the second set of parenthesis, giving us the equation 7t-35=5t+15. We now simplify:
$2t=50 \\\\ t=25$