To approach this question, you need to think of simple algebra and what the question is asking for. If they want c to be the subject of the formula, they are looking for the answer to be in terms of c. To put this simply, they're asking for the answer to equal c (i.e c=the rest of the equation). Therefore, we need to rearrange this equation to put the c term on one side and cancel it so it is only equal to c and not 3c. first step : a+12=3c (here I have added 4 onto the left side to make the c term the only term on the right)second step: a/3+4=c (now I have divided the equation by 3 so that we are making c the subject of the formula by changing it from 3c to c)
answer: c=a/3+4