Question 355647
let price of pen be $x
price of notebook be $y/10
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10x+10y=20
x+y=2.......................1
5x+8y=15....................2
multiply equation 1 by -5 and add it to equation2
-5x-5y=-10
add to 2
8y-5y=15-10
3y=5
/3
y = 5/3
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plug value of y in equation 1
x+5/3 = 2
(3x+5)/3=2
3x+5 =6
3x=6-5
3x=1
x= 0.33
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Pen costs 33 cents 
notebook costs $1.67
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m.ananth@hotmail.ca