Final answer:
Expression B has the greatest value with 16.
Step-by-step explanation:
To determine which expression has the greatest value, we need to evaluate each one step by step.
Expression A: 1-3 + 4.91 = 2.91
Expression B: 15-6 + 7 = 16
Expression C: 1-2 + 8 + 1 = 8
Based on the evaluations, Expression B has the greatest value with 16.