Will mark brainiest

2.) find the sum and choose the correct answer.

2n^3 + 4n^2 - 7 and -n^3 + 8n - 9

a.) -n^3 - 4n^2 - 8n - 16
b.) n^3 + 4n^2 + 8n - 16
c.) n^3 + 4n^2 + 8n + 16
d.) 3n^3 + 4n^2 + 8n - 2

What is the distance between the points (2, 5) and (5,9)?

Choose the correct translation for the following statement. it is at most ten. x< 10 x< 10 x> 10 x> 10

For every corresponding pair of cross sections, the area of the cross section of a sphere with radius r is equal to the area of the cross section of a cylinder with radius and height 2r minus the volume of two cones, each with a radius and height of r. a cross section of the sphere is and a cross section of the cylinder minus the cones, taken parallel to the base of cylinder, is the volume of the cylinder with radius r and height 2r is and the volume of each cone with radius r and height r is 1/3 pie r^3. so the volume of the cylinder minus the two cones is therefore, the volume of the cylinder is 4/3pie r^3 by cavalieri's principle. (fill in options are: r/2- r- 2r- an annulus- a circle -1/3pier^3- 2/3pier^3- 4/3pier^3- 5/3pier^3- 2pier^3- 4pier^3)