Question

1.
EXERCISE 4.1
The cost of a notebook is twice the cost of a pen. Write a linear equation in two
variables to represent this statement.
(Take the cost of a notebo​

Answer 1

✬ Equation = x – 2y = 0 ✬

Step-by-step explanation:

Given:

• Cost of a notebook is twice the cost of a pen.

To Write:

• Linear equation in two variables.

Solution: Let the cost of a pen be Rs y and cost of a notebook be Rs x. Therefore,

➱ Cost of a notebook = 2 times of cost of pen

➱ Cost of a notebook = 2 times of y

➱ x = 2y or

➱ x – 2y = 0 [ Transported to LHS from RHS ]

Hence, x – 2y = 0 is the linear equation in two variable.

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★ What is linear equation in two variable ?

=> An equation which in the form of ax + by + c = 0, where a , b , c are real numbers and a and b are not both zero ( a ≠ 0 , b ≠ 0 ) , then it is called a linear equation in two variable x and y.

Answer 2

Step-by-step explanation:

Let the cost of a notebook be Rs. x and that of a pen be Rs. y.

Given the cost of a notebook is twice the cost of a pen.

Then x=2y

or, x−2y=0.

This is the required linear equation in two variable.