Question

Suppose a - b = 0Which of the these expressions equals ab?

Answer 1

We are given the expression:

$a-b=0$

To simplify

Let us add b to both sides

$a-b+b=0+b$

Simplifying further

$a=b$

Then, we are told to find the value of ab

$\begin{gathered} ab=a\times b \\ \sin ce\text{ } \\ b=a \\ \text{then} \\ a\times b=a\times a=a^2 \\ ab=a^2 \end{gathered}$

Thus the answer is

a² (option A)