X(2x+1)(5x-30)≤0

I'm confused help

Two planes leave an airport at the same time, one flying east, the other flying west. the eastbound plane travels 20 mph slower. they are 1600 mi apart after 2 hr. find the speed of each plane.

If you can solve all of these i will give ! - 4% of 190 - 4% of 162.5 - 4% of 140 - a 4% increase from 155.1 - a 4% increase from 159.8

Amachine part consists of a half sphere and a cylinder, as shown in the figure. the total volume of the part is π cubic inches.