Question

Factorise the following expression: $16z + 20{z^3}$.
$
  {\text{A}}{\text{. }}4z\left( {2 - 5{z^2}} \right) \\
  {\text{B}}{\text{. }}4z\left( {4 + 5z} \right) \\
  {\text{C}}{\text{. }}4z\left( {4 + 5{z^2}} \right) \\
  {\text{D}}{\text{. 4z}}\left( {2 + 5{z^2}} \right) \\
$

Answer 1

Hint: In this question, we will take out all the common factors from the whole expression. This will help us simplify the expression and get us to our answer.

Complete step-by-step answer:

We have been given the expression: $16z + 20{z^3}$
As, 4z is common in both the terms
So, $16z + 20{z^3} = 4z\left( {4 + 5{z^2}} \right)$
So, the correct option is C.

Note: Whenever we face such types of problems the value point to remember is that we need to have a good grasp over factorisation. We must also remember that in factorised form we need to take all the common factors from all the terms. This helps in getting us the required expressions and gets us on the right track to reach the answer.