Question

Find the value of the product $4\times (-9)$.

• A. $36$
• B. $13$
• C. $-36$
• D. $-13$

Answer 1

The correct option is C $-36$

$4\times (-9)$ can be written as $-(4\times 9)$.

$(4\times 9)$, i.e., multiplying $4$ by $9$ denotes $9$ times addition of $4$ or $4$ times addition of $9$.

Now, $9$ when added $4$ times would give the value as $\underset{–}{9+9}+\underset{–}{9+9}=18+18=36$.

Hence, $4\times 9=36$.

$\therefore 4\times (-9)=-(4\times 9)=-36$

Therefore, (c.) is the correct option.