Final answer:
To make the triangle isosceles, the value of t is 6.
Step-by-step explanation:
An isosceles triangle is a triangle that has two sides of equal length. To determine the value(s) of t that make the triangle isosceles, we need to set the two sides with equal length equal to each other and solve for t.
Setting 3t = 5t - 12, we can solve for t:
3t = 5t - 12
12 = 5t - 3t
12 = 2t
t = 6
Therefore, the value of t that makes the triangle isosceles is 6.