Y varies directly as x. When x = 9, y = 27

Find y when x = 27

Can some one me with these questions

Find the volume of the solid obtained by rotating the region enclosed by the curves y=1x and y=7^-x about the x-axis. (use symbolic notation and fractions where needed.) volume =

Calculate the total payback for a $3,500 loan at 8% annual interest with monthly payments for two years. show all of your steps. use the formula, m = pm(1 + m)^na/(1 + m)^na - 1, as needed.