Which of the following relations is a function?
{ (-2, 4), (-1, 3), (5, 2), (1, 4) }
{ (1, 7), (1, 8), (2, 7), (3, 8) }
{ (2, 4), (4, 6), (4, 8), (6, 4) }
{ (5, 7), (6, 3), (8, 6), (5, 4) }

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

What is the total area of the figure?

Which function has an inverse function? a.f(x)= |x+3|/5 b. f(x)= x^5-3 c. f(x)= x^4/7+27 d. f(x)= 1/x²