Step 1 is wrong it should be: 2x - 3x - 1=3
ANSWER
B.Yes, f is continuous on [1, 7] and differentiable on (1, 7).

EXPLANATION
The given

The hypotheses are
1. The function is continuous on [1, 7].
2. The function is differentiable on (1, 7).
3. There is a c, such that:


This implies that;




Since the function is continuous on [1, 7] and differentiable on (1, 7) it satisfies the mean value theorem.