Use the shell method to set up and evaluate the integral that gives the volume of the solid generated by revolving the plane region about the x-axis. y = x2
x = 0
y = 16

the 3rd on is correct

step-by-step explanation:

i honestly dont know

this is a direct variation proportion. y = kx

y is the total amount due, k is the constant of variation, and x is the number of texts sent.

plug in the 3.20 and the 16 to solve for the "k". this is the constant of proportionality. it is the value that will not change.

3.20 = k(16). solving you get $.20 per text.

the equation would then be y = .20x