Question 3
Fractions, Decimals and ApproximationWhich of the following is NOT a factor of 124 − 54?
- A.7
- B.13
- C.17
- D.49
- E.169.
Show the answer and explanation
Answer: D (49)
Explanation
12⁴ − 5⁴ = (144 + 25)(144 − 25) = 169 × 119 = 13² × 7 × 17. It contains only one 7, so 49 is not a factor.