Which expression could be used to solve this problem?

bart practices piano every day. first he practices songs for 20 minutes. then he practices scales for 15 minutes. how much time does bart practice piano in 3 days?

a.
3 × (20 – 15)

b.
20 × (15 + 3)

c.
3 × (20 + 15)

d.
20 × (15 – 3)

What is the exact volume of the cylinder? 16in going into the middle of the top of the cylinder and 40in in height a) 25,600(pi)3 b)10,240(pi)3 c)1280(pi)3 d)640(pi)3

Write an equation of a line in slope intercept form that is perpendicular to the line 2x -3y = 12 and passes through the point (2, 6).

1. writing an equation for an exponential function by 2. a piece of paper that is 0.6 millimeter thick is folded. write an equation for the thickness t of the paper in millimeters as a function of the number n of folds. the equation is t(n)= 3. enter an equation for the function that includes the points. (-2, 2/5) and (-1,2)