Question

5 pencils and 7 pens together cost Rs 50, whereas 7 pencils and 5 pens together
cost Rs 46. Find the cost of one pencil and that of one pen.​

Answer 1

Explanation:

and graph is there..

hope it helps

Answer 2

$let \: the \: no. \: of \: pencils \: be \: x \\ \: \: and \: the \:no . \: of \: pens \: \: be \: y. \\ 5x + 7y = 50 \\ \: x = (50 - 7y) \div 5 \\ x = 10 - 7y \div 5 \\ 7x + 5y = 46 \\ put \: the \: value \: of \: x \: in \: the \: \\ above \: equation. \\ 7(10 - 7y \div 5) + 5y = 46 \\ 70 - 49y \div 5 + 5y = 46 \\ 70 - 46 = 49y \div 5 - 25y \div 5 \\ 24 = 24y \\ y = 1 \\ so \: there \: is \: 1 \: pen.$