Question

3. Siri bought 2 notebooks and 3 pens for Rs 90 .Lakshmi bought 4 notebooks and 5 pens for Rs 140. Form linear equations for the givensituation to find the cost of a pen and a notebook .​

Answer 1

Step-by-step explanation:

Let book, notebook, pen be x, y, z respectively.

2x+6y+3z=40

3x+4y+2z=35

5x+7y+4z=61

⎣⎢⎢⎡235647324⎦⎥⎥⎤⎣⎢⎢⎡xyz⎦⎥⎥⎤=⎣⎢⎢⎡403561⎦⎥⎥⎤

Apply R1→R1−R2

⎣⎢⎢⎡−135247124⎦⎥⎥⎤⎣⎢⎢⎡xyz⎦⎥⎥⎤