Each friend should get 1/5 of a bag of trail mix. Since there are three bags of trail mix, you would add those into it. Hope this helps!
When you are asked to solve an equation, you need to isolate the variable which is t in this case. To isolate t, you would divide both sides by -5 and be left with t=-6 which is the final answer.
I hope this helps.
The answer is A. This is because in A, you are subtracting 2 from X, instead of X from 2.