Which one you need help on?
Use dimensional analysis:

Since we multiplied a numerator and a denominator by centimeters, we are only left with meters.
This answer is already is three significant figures by default.
Answer:
15
Step-by-step explanation:
<span> f(x) = x^2 + 4x − 1 and g(x) = 5x − 7
</span>(fg)(x) = (x^2 + 4x − 1)(5x − 7)
(fg)(x) = 5x^3 + 20x^2 - 5x - 7x^2 - 28x + 7
(fg)(x) = 5x^3 + 13x^2 - 33x + 7
answer is C. third choice
(fg)(x) = 5x^3 + 13x^2 - 33x + 7