What is the answer to Question 4 and Question 5?

The denominator is $\sqrt{10}-3$. The conjugate of an expression of the form $a-b$ is $a+b$.
So, the conjugate of $\sqrt{10}-3$ is $\sqrt{10}+3$.

To rationalize the denominator, we multiply the fraction by $\frac{\text{conjugate}}{\text{conjugate}}$. In this case, we multiply by $\frac{\sqrt{10}+3}{\sqrt{10}+3}$. The question asks what we multiply the fraction by, which refers to the expression used in the numerator and denominator to achieve rationalization. Among the given options, $\sqrt{10}+3$ is the key part of this multiplying factor.

The correct option is B.

Length ($l$) = $5 \text{ m}$
Width ($w$) = $4 \text{ m}$
Height ($h$) = $3 \text{ m}$

The surface area ($SA$) of a cuboid is given by the formula:

The correct option is B.

This is a product of conjugates of the form $(a-b)(a+b)$.

The formula for the difference of squares is $(a-b)(a+b) = a^2 - b^2$.
Here, $a=8$ and $b=\sqrt{3}$.

The correct option is A.

Like terms are terms that have the same radical part.
The terms with $\sqrt{2}$ are $7\sqrt{2}$ and $-6\sqrt{2}$.
The term with $\sqrt{3}$ is $5\sqrt{3}$.

Combine the terms involving $\sqrt{2}$:

The term $5\sqrt{3}$ cannot be combined with $\sqrt{2}$ because they have different radical parts.

The correct option is C.