Question

by increasing the number of federal hazardous waste sites in state A by 3 and then dividing by 3, the result is the number of federal hazardous waste sites in state B . find the number of federal hazardous waste sites in state A if there are 12 such sites in state b.

Answer 1

$\bf \textit{let's add 3 to A}\implies A+3 \\\\\\ \textit{now divide it by 3}\implies \cfrac{A+3}{3} \\\\\\ \textit{so hmm B is equals to that}\implies \cfrac{A+3}{3}=B \\\\\\ \textit{if B=12, what is A?}\implies \cfrac{A+3}{3}=12$

solve for A