00:01
If you're driving a court whose fuel efficiency is 19 mpg in the city and 26 mpg on the highway, and you make a distant you travel a distance of 300 and 49.5 miles on 16 leaders.
00:19
And how far did you drive in the city? and how far did you drive on the highway? since we want to answer this question by finding any number of miles of city driving and the number of miles of highway driving, let's call these x and water the distance in the city.
00:40
X in the distance in the on the highway is what.
00:46
And so how do we solve this year? this question? well, we know.
00:53
In total, the distance was 349.5 miles.
00:57
And so if x of those miles were in the city, and why on the highway x plus y is 349.5? no, since we want to solve for both variables x and why we need a system of two equations.
01:19
Whenever we have two variables, we need two equations.
01:26
So where does the other equation come from? well, we used the distance information, but we haven't used the fuel efficiency and amount of fuel information to find an equation.
01:45
Using this information first started here.
01:51
16 gallons of people were used altogether.
01:54
But can we express amounts of fuel in terms of x and y and then had those quantities up to get 16 as a total? of course we can...