### Video Transcript

Using 𝑥 to represent the cost of a
notebook and 𝑦 to represent the cost of a folder, write an expression for the cost
of three notebooks and two folders. Then find the total cost, given
that the notebooks are one dollar and 69 cents each and the folders are zero dollars
and 59 cents each.

Well, if we’re going to form our
expression, we can see that we’ve got 𝑥, which represents the cost of a
notebook. And we’re gonna have three
notebooks. So we can write three 𝑥. And then we’ve got 𝑦, which gonna
represent our folders. And we’ve got two folders, so we’re
gonna add this. So therefore, our expression for
the cost of three notebooks and two folders is three 𝑥 plus two 𝑦.

Okay, great, so now let’s move on
to the second part of the question cause we want to find the total cost given that
the notebooks are one dollar and 69 cents each and the folders are zero dollars and
59 cents each. So what we’re gonna do is we’re
gonna substitute in some values for our 𝑥 and 𝑦. So we know that our 𝑥 is gonna be
one dollar and 69, and our 𝑦 is gonna be zero dollars and 59 cents. So therefore, to calculate the
total cost, what we’re gonna do is three multiplied by 1.69 plus two multiplied by
0.59, which is gonna give us 5.07 plus 1.18. Which gonna give a total cost for
the three notebooks and two folders of six dollars and 25 cents. Okay, great, so we’ve solved this
problem. And we’ve found our expression and
our total cost.