2,640/k=11 what is the value of k

Match each statement with its corresponding value for the system below: y = -2(3)x and y = 9x - 2 1. the number of points of intersection. -2 2. the x-coordinate of the solution. 1 3. the y-coordinate of the solution. 0

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 =

Given that sin∅ = 1/4, 0 < ∅ < π/2, what is the exact value of cos∅? a. (√4)/4 b. (√15)/4 c. (4π)/2 d. (4√2)/4