Please answer A-C

' An office machine is purchased for $7800; Assume that its salvage value, V, in dollars. depreciates, according to a ' \" ' method called double declining balance. by 20% each year and is given by V(t) = 7800(0.80)', where t is the \"time, in years, after purchase. ' a) Find V(9), and explain its meaning. b) Find V'('9). and explain its meaning. c) When will the salvage value of the pice machine be half of the purchase price? Q a) V(9l=s =- (Round to the nearest cent as needed.)