Need help with all 3!

If a and −a are numbers on the number line, which expression must give the distance between them? a) 0 b) a c) |2a| d) |a|

Suppose that 15 inches of wire cost 60 cents. at the same rate, how much (in cents) will 12 inches of wire cost

A) find the derivative of the inverse to f(x) = 3x + sint at x 6. b) (cale) find the derivative of the inverse to f(x)+3sin at x 6. if x +2y -34, ind he behaviar of the cure at 4,.3), c) a. increasing, concave up d. decreasing, concave down b. increasing, concave down e. decreasing, inflection point c. decreasing, concave up