Question

5 pencil and 7 pens together cost rupees 50 ,whereas7 pencils and 5 pens together cost rupees 46. Find the cost of one pencil and that of one pen solve it

Answer 1

Answer:

let cost of a pencil=x and cost of a pen=y

then 5x+7y=50 --------(1)

7x+5y=46--------(2)

(1)×7 : 35x+49y=350--------(3)

(2)×5 : 35x+25y=230--------(4)

that is, (3)-(4): 24y= 120

or, y=5

put value of 'y' in equation(1).then we get ..x=3

or; cost of a pencil= 3 rupees

cost of a pen=5 rupees

Answer 2

Step-by-step explanation:

5x+7y=50 5x=50-7y

5(7x+5y=46)

7.5x+25y=230

7.(50-7y)+25y=230

350-49y+25y=230

-24y=230-350

-24y=-120

y=-120÷-24

y=5

5x=50-7(5)

5x=50-35

5x=15

x=3