2. one pair of perpendicular segments

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

If f(x) =3x-2 and g(x) =2x+1 fins (f+ g) (x)

Is this a polynomial function? i need to know asap