Geometry help what is it

Simplify the expression. -2/5(10+15m-20n)

Me i'm timed right now! a. (0,-5)b. (0,-3)c. (0,3) d. (0,5)

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.