The function y = 2.15 + 1.3(x - 2) can be used to determine the cost in dollars for driving x miles. What is the rate of change of the cost in dollars with respect to the number of miles?

Really need on these. i have no idea what to do

Mr switzer needs to buy new 1-foot tiles to cover his bathroom floor. the floor is 12 feet long and 8 feet wide. each square foot of tile will cost $1.79. in dollars what will be the total cost of the tiles he needs to buy.

Line l passes through points (0,4) and (3,6) what is the slope of a line that is parallel to line l -2/3 -3/2 2/3 3/2