7=5y-13-y Solving linear equations please help m i need your help

20 points for you if you help me please

Me because some of question i don’t understand

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)

Select the correct answer. which exponential function has an x-intercept? oa. (x) - 100x-5-1 ob. (x) = 3x4+2 oc. kx) = 7x-1 + 1 od. 1(x) =-3x+1 - 3