Question

EXERCISE 3.2
Form the pair of linear equations in the following problems, and find th
graphically.
(1) 10 students of Class X took part in a Mathematics quiz. If the numbe
more than the number of boys, find the number of boys and girls wh
the quiz.
i 5 pencils and 7 pens together cost Rs 50, whereas 7 pencils and 5 p
cost Rs 46. Find the cost of one pencil and that of one pen.​

Answer 1

Answer:

cost of pencil=x

cost of pen=y

5pencils and 7 pens cost=50

5x+7y= 50

7pencils =x

5pens=y

7pencils and 5pens cost=46

7x+5y=46

Explanation:

5x+7y=50 ×2= 10x+14y=100

7x+5y=46 ×2= 14×+10u=92

-4×+4y=18