Question

5pencils and 7 pens together cost rupee 50. whereas 7pencils and 5 pens cost rupee 46 . find the cost of one pencil and that of one pen represent graphically of classX question​

Answer 1

Answer: let the cost of  pencil is x and the cost of pen is y

now, 5x + 7y = 50

⇒5x = 50 - 7y

⇒x = $\frac{50 - 7y}{5}$ ..................................(i)

also,

7x + 5y = 46

⇒ 7x = 46 - 5y

⇒ 7 $*\frac{50 - 7y}{5}$ = 46 - 5y ........................................from equation (i)

⇒ 350 - 49y = 230 - 25y

⇒ 350 - 230 = 49y - 25y

⇒ 120 = 24y

⇒ 120/24 = y

⇒  y = 5

∴ x = 50 - 7y / 5

⇒ x = 50 - 35 / 5

⇒ x = 15  /5

⇒ x = 3

∴ cost of pencil = Rs.3

and cost of pen = Rs.5

Step-by-step explanation:

Answer 2

Answer:

cost of one pencil = 3

cost of one pen = 5

hope it helps u........