Help exam starts in a min!!!

Ashopper bought a watermelon a pack of napkins and some paper plates in his state there was no tax on food the tax rate on non-food items is 5% the total for the three items he bought was 825 before tags and he paid $0.19 in taxes how much did the watermelon cost

Three times the sum of a number and seven is negative thirty-six. what is the number?

Which letters from the table represent like terms? a and b b and c a and d b and d