The total cost of 6 books and7 pens is79 and the total cost of 7 books and 5 pens is 77 find the cost of 1 book and 2 pens
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Let cost of a single book be x
Let cost of a pen be y
So, we have two equations,
6x+7y=79...1
7x+5y=77...2
Simultaneously, solving both equations:
Multiplying (1) by 5 and (2) by 7,we get
30x+ 35y=395(a)
49x+35y=539(b)
Subtracting,
(b-a)
19x=144
x=144/19
put this in eqn you get value of y
Let cost of a pen be y
So, we have two equations,
6x+7y=79...1
7x+5y=77...2
Simultaneously, solving both equations:
Multiplying (1) by 5 and (2) by 7,we get
30x+ 35y=395(a)
49x+35y=539(b)
Subtracting,
(b-a)
19x=144
x=144/19
put this in eqn you get value of y
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