How to simplify a 3 - 2 a b + 3 a 3 + 4...

Problem: 3 Marks
Given, weight of man on earth, $W_e=600$ N
weight of man on moon, $W_m=100N$ and acceleration due to gravity, $g=9.8m{s}^{-2}$
Let 'm' be the mass of the man.
We know, W=m×g
∴$W_e=m\times g$
$\Rightarrow m=\frac{We}{g}=\frac{600}{9.8}=61.22$ kg
Therefore, the mass of man on the earth is 61.22 kg. Then, the mass of a body remains the same everywhere in the universe. So, the mass of man on the moon will also be 61.22 kg.
Using the same formula, we will now calculate the value of acceleration due to gravity on the moon:
W=m×g
i.e, $W_m=m\times g$
where mass, m=61.22 kg
$\Rightarrow g=\frac{W_m}{m}=\frac{100}{61.22}=1.633m{s}^{-2}$
Hence, acceleration due to gravity on the moon is $1.633m{s}^{-2}$.