Question

the cost of 2 pencils and 3 erasers is Rs. 9 and the cost of 4 pencils and 6 erasers is Especially. 18. Find the cost of each pencil and each eraser.

Answer 1

Hy,
Let the cost of pencil be x, eraser be y.
From 1st statement,
2x+3y=9
From 2nd statement,
4x+6y=18
From Eq 1, x=9-3y/2
Substituting the value of x in Eq 2,
4x+6y=18
Implies 4(9-3y/2)+6y=18
Implies 36-8y/2+6y=18
Implies 36-8y+12y/2=18
Implies 36+4y=18*2
Implies 36+4y=36
y=0/4=0
Implies it has no solution....
Thanks

Answer 2

Hi!

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The Pair of Linear Equation formed were

2x + 3y = 9 ---> 1

4x + 6y = 18 ----> 2

Express the Value of x in terms of y from eq (1)

2x + 3y = 9

$x = \frac{9 - 3y }{2}$

Now Substitute the value of x in eq (2)

4x + 6y = 18

$\frac{4(9 - 3y}{2} + 6y = 18$

18 - 6y + 6y = 18

18 = 18

Hence , there are many Common Solutions to the given Situation

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Thanks !