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## Heart of algebra

# Linear function word problems — Basic example

## Video transcript

- [Instructor] We're told Fara watched two different TV shows last week. TV show A has 11-minute episodes, and TV show B has 43-minute episodes. Together, she spent 196
minutes watching TV shows. Which equation models this relationship, where lowercase a is the
number of TV show A episodes and lowercase b is the number of TV show
B episodes Fara watched? So pause this video and
have a go at it on your own before we work through this together. All right, now, let's do this together. So we know that together,
she spent 196 minutes watching TV shows. So what we wanna do is
total the amount of time she spent watching TV show A, the amount of time she
spent watching TV show B, and then that should be equal to 196. And so, actually, let me just do TV show A in this orange color. How much time did she
spend watching TV show A? Well, we know that each
episode of TV show A is 11 minutes. So it's going to be 11 minutes times the number of episodes. And they said that lowercase a is the number of TV show A episodes. So this right over here, 11a, is how much time she
spent watching TV show A. And what about TV show B? Well, each episode is 43 minutes. So it's going to be 43
minutes per episode. And how many episodes
are there of TV show B? Well, it's lowercase b is the
number of TV show B episodes. So 43 minutes per episode
times lowercase b episodes, that's how much time she
spent watching TV show B. So if you add the amount of
time she watched TV show A to the amount of time she
spent watching TV show B, that will be her total time, and we know that that needs to be equal to 196. And so let's see which
of these choices have it. That's not that one. Let's see, this one is it, exactly what we got. This is different, and this is different. And we're done.