00:01
So in this problem, it's saying pretty much in 1954, roger bannister cracked the four minute mark.
00:12
So he set the record for a mile in three minutes and 59 .4 seconds.
00:19
We don't care about that.
00:20
We just want to know that it's 239 .4 seconds.
00:26
And it's giving us a linear equation that we want, that it wants us to write a linear equation based on their information it's giving us.
00:33
So it's saying the record has decreased by 0 .3 seconds each year.
00:39
So basically, we want to write a function.
00:44
So it'll be f of x equals what we started with, 239 .4.
01:02
And since we're decreasing each year, we're going to subtract whatever we're decreasing by.
01:09
So we're going to subtract 0 .3.
01:14
And since that is the rate that we're decreasing by each year, we're going to put an x to represent a year.
01:28
So basically this is the answer because it just wants the function.
01:40
But if we want to solve b, it's asking if this trend continues, basically the trend of decreasing by 0 .3 seconds per year after 1954, what year will someone run a three -minute mile? or 180 seconds...