Correct Answer:
C. 54.9
To solve the expression 5 + 51 + (−3) + 7 + (−5.1)7, we must follow the order of operations. Assuming '(-5.1)7' is a typographical error and should be interpreted as just '(-5.1)' to match the provided correct answer, the calculation proceeds as follows:
- 5 + 51 = 56
- 56 + (−3) = 53
- 53 + 7 = 60
- 60 + (−5.1) = 54.9
Thus, the correct result is 54.9. The other options would arise from different interpretations of the last term or arithmetic errors.