How do you solve -84=d/3?

May 1, 2017

Multiply both sides by $3$ to isolate $d$

Explanation:

$- 84 \cdot 3 = \frac{d}{\cancel{3}} \cdot \cancel{3} \to - 252 = d$

May 1, 2017

$d = - 252$

Explanation:

The objective is to have $d =$something. So we need to get the $d$ on its own

Note that $\frac{d}{3}$ is the same as $\frac{1}{3} \times d$

So if we can change the $\frac{1}{3}$ into 1 then we have $1 \times d$ which is the same as just d.

What we do to one side of the equation we also do to the other.

Multiply both sides by $\textcolor{red}{3}$

$\textcolor{g r e e n}{\left(- 84\right) \textcolor{red}{\times 3} = \frac{d}{3} \textcolor{red}{\times 3}}$

$- 252 = d \times \frac{3}{3}$

but $\frac{3}{3} = 1$

$d = - 252$