SOLUTION: Applications of linear systems- solve using two equation and two variables An office suply store in San Diego sells 7 writing tablets and 4 pens for $6.40. Also, 2 tablets an

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Question 300769: Applications of linear systems- solve using two equation and two variables

An office suply store in San Diego sells 7 writing tablets and 4 pens for $6.40. Also, 2 tablets and 19 pens cost $5.40. Find the price of each one
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Let W be the price of writing tablets, P be the price of pens.
1.7W%2B4P=6.40
2.2W%2B19P=5.40
Multiply eq.1 by 2 and eq. 2 by (-7) and add them together to get rid of W.
%2814W%2B8P%29%2B%28-14W-133P%29=12.80-37.80
125P=25
P=0.2
Then use either equation to solve for W.
7W%2B4P=6.40
7W%2B4%280.2%29=6.40
7W%2B0.80=6.40
7W=5.60
W=0.80
Writing tablets are $0.80 and pens are $0.20.