Please help need right answer

Abacteria population is tripling every hour. by what factor does the population change in 1/2 hour? select all that apply

If f(x) = 4x - 3 and g(x) = x + 4, find (f - g) (x)

Long division setup showing an incomplete calculation. 12 is in the divisor, 6839 is in the dividend, and 5 hundreds and 6 tens is written in the quotient. 6000 is subtracted from 6839 to give 839. an unknown value represented by a box is being subtracted from 839. what number should be placed in the box to complete the division calculation?