4. Combine the two equations to eliminate one of the variables, and then solve for the other. (3 points: 1 for eliminating one variable, 1 for the answer, and 1 for showing your work) 4.3.4 journal. Need help asap

The volume of a spherical hot air balloon v(r) = 4 3 ? r3 changes as its radius changes. the radius is a function of time given by r(t) = 3t. find the instantaneous rate of change of the volume with respect to t at t = 2.

David and alton are training for a race. they spend 35 minutes stretching and then go on a 5 mile practice run. david runs at a pace of 7 min/mile. alton runs at a pace of 8 min/mile. write an equation for each runner that shows the total length of their workout. then solve each equation showing your work

Louis wants to give \$15 to kids who need school supplies. he also wants to buy a pair of shoes for \$39. how much money will he have to save for both?