Need the half amount please help

step-by-step explanation:

b and c

m∠a is 90°

m∠b is 40°

answer:

at time x=0 we have 1000, at time x=1 we have 2000, at time x=2 we have 4000.  

so that's an initial value of 1000 and a ratio of 2,

y = 1000 (2^x)

hope this !