00:01
So here we're told that in 2014, the world's oil reserves had 1 ,820 billion barrels, and each year it's depleting by 25, it would be decreasing by 25 billion barrels of oil each year.
00:17
So we're told to give a linear equation for part a.
00:22
So for part a, we know that the slope, the slopes, so we're going to set r -o -t, because we have to say remaining oil reserves are in terms t.
00:33
So r of t is equal to negative 25t plus the initial number of barrels in 2014, which is $18 ,000, $1 ,820 billion.
00:47
So we're just going to write $1 ,820.
00:50
So t stands for the number of years after 2014 and 25.
00:58
Is the constant rate because it says 25 billions per year.
01:02
The negative is because it's decreasing that much each year.
01:06
And this would be the initial value...