Question

the cost of the pen is thrice the cost of the pencil. also 2 pens and 3 pencils together cost rupees 45. represent the above statement by two linear equations in two variables.

Answer 1

Let cost of pen= x rs
Let cost of pencil= y rs
According to 1st condition
X=3y
i.e. x-3y =0
According to 2nd condition
2x+3y=45
i.e. 2x+3y-45=0
These are req. Equations

Answer 2

Let, cost of

• pencil = x
• pen = y

××××××××××××××××××××××

Cost of pen = 3× cost of pencil

y = 3× x

y = 3x -----1equation



================

According to the question,


Cost of 2pens + cost of 3pencils = 45

2(y) + 3(x) = 45

2y + 3x = 45

Putting the value of 3x from 1equation

2y + y = 45

3y = 45

y = 45/3

y =15


Putting the value of y in 1equation,

y = 3x

15 = 3x

15/3 = x

5 = x

====================

Cost of pencil = x = ₹5
Cost of pen = y = ₹15



I hope this will help you

(-: