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4 votes
One month Tammy rented

3
movies and
2
video games for a total of
$20
. The next month she rented
8
movies and
4
video games for a total of
$45
. Find the rental cost for each movie and each video game.

1 Answer

4 votes

3x + 2y = 20

8x + 4y = 45

where x = # of movies and
y = # of video games

In order to solve this systems of equations problem, you need to use the elimination method.

You can multiply the top equation,
3x + 2y = 20, by -2 in order to eliminate the
y values.


(3x + 2y = 20) *-2 will turn into
-6x - 4y = -40

From there, we can eliminate.


-6x - 4y = -40

8x + 4y = 45

Since
4y and
-4y are opposites in sign and equal in coefficients, we can remove them from our equations and add the rest of the terms together.


-6x - 4y = -40

8x + 4y = 45
will turn into -->

2x = 5

So, x =
(5)/(2), which means 1 movie costs $2.50. Then, we can solve for the video game price,
y, by substituting our x back into one of the equations.


3x + 2y = 20

3*<span>(5)/(2)&nbsp;</span>+ 2y = 20

y = (25)/(4)

Each movie costs $2.50 and each video game costs $6.25.
User Jarober
by
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