Question 152634This question is from textbook elementary and intermediate algebra concepts and applications
: Can somebody please help me I forgot how to do these problems?
Translate the following into a system of equations, then solve it:
A customer walks into an electronics store and buys five MP3 players and eight sets of headphones, paying $840. A second customer buys three MP3 players and four sets of headphones, and pays $480. How much does an MP3 player cost? How much does a set of headphones cost?
(i) What are the x-intercept and y-intercept of a linear equation?
(ii) What are their coordinates on a graph?
(iii) How can they be used to graph a line?
(iv) Demonstrate by determining the intercepts of "14x + 7y = 21".
This question is from textbook elementary and intermediate algebra concepts and applications
Answer by Fombitz(32388)   (Show Source):
You can put this solution on YOUR website! Let M be the price of an MP3 player, H the price of the headphones.
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First customer: 5 MP3 players, 8 headphones, $840
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Second customer: 3 MP3 players, 4 headphones, $480
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Now you have two equations in two unknowns, M and H.
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2.
Use 1 to come up with an expression for M in terms of H.
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Substitute this expression into 2 and solve for H.
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From above,
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And now for something completely different.
X intercept: where the line crosses the X axis.
Coordinates are ( , ).
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Y intercept: where the line crosses the Y axis.
Coordinates are (, ).
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You only need two points to graph a line.
If you have both the the x and y intercepts, those are two points you could use to graph the line.
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For the x intercept, set y=0, solve for x.
(3/2,0)
Graph it.
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For the y intercept, set x=0, solve for y.
(0,3)
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The last step is to draw a line connecting those two points.
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