One model for the time it will take for the world’s oil supply to be depleted is given by the function t(r) = 14.29 ln(0.00411r + 1), where r is the estimated oil reserves in billions of barrels and t is the time in years before that amount of oil is depleted. use this function to answer the questions below. (round to the nearest billion barrels.) how many barrels of oil are necessary to last 30 years? how many barrels of oil are necessary to last 60 years?

x> 6

step-by-step explanation:

8x+8> 7x+14

8x-7x> 14-8

x> 6

sine

step-by-step explanation:

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional