в) 2t + 5t + 3,18 = 25,3

1. Combine like terms: 7t + 3,18 = 25,3.
2. Isolate the term with t: 7t = 25,3 - 3,18 = 22,12.
3. Solve for t: t = 22,12 / 7.
4. Result: t = 3,16.