Question

The cost of a pen is ₹(x + 4), Radhika
bought (x + 4) pens. Find the total amount
paid by her in terms of x. If x = 10, find the
amount paid by her.


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Answer 1

Step-by-step explanation:

Let the cost of a pen and a pencil be x and y respectively.

4x+4y=100

x+y=25 ...(1)

3x=y+15

3x−y=15 ...(2)

Adding (1) and (2), we get

4x=40

x=10

Substitute x=10 in equation (1) to get y=15.