SOLUTION: Jada and Shakerra bought some markers and pens. Jada bought 4 markers and 5 pens and it costs her $671. Shakerra bought 5 markers and 3 pens, which cost her $7.12. What is the pric

Algebra ->  Equations -> SOLUTION: Jada and Shakerra bought some markers and pens. Jada bought 4 markers and 5 pens and it costs her $671. Shakerra bought 5 markers and 3 pens, which cost her $7.12. What is the pric      Log On


   

Question 1112435: Jada and Shakerra bought some markers and pens. Jada bought 4 markers and 5 pens and it costs her $671. Shakerra bought 5 markers and 3 pens, which cost her $7.12. What is the price for one marker and one pen?
Found 2 solutions by josgarithmetic, josmiceli:
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
(Decimal point in Jada's purchase was left out but I put it in.)


m, price of Marker
p, price of Pen

system%284m%2B5p=6.71%2C5m%2B3p=7.12%29


This step may prepare for elimination method:
system%283%284m%2B5p%29=3%2A6.71%2C5%285m%2B3p%29=5%2A7.12%29
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Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = the cost of 1 marker in cents
Let +b+ = the cost of 1 pen in cents
-----------------------------------
(1) +4a+%2B+5b+=+671+
(2) +5a+%2B+3b+=+712+
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Multiply both sides of (1) by +3+
Multiply both sides of (2) by +5+
and subtract (1) from (2)
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(2) +25a+%2B+15b+=+3560+
(1) +-12a+-+15b+=+-2013+
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+13a+=+1547+
+a+=+119+
and
(1) +4a+%2B+5b+=+671+
(1) +4%2A119+%2B+5b+=+671+
(1) +476+%2B+5b+=+671+
(1) +5b+=+195+
(1) +b+=+39+
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One marker costs $1.19
One pen costs $.39
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check answers:
(2) +5a+%2B+3b+=+712+
(2) +5%2A119+%2B+3%2A39+=+712+
(2) +595+%2B+117+=+712+
(2) +712+=+712+
OK