Question

5 pencils and 7 pens together cost Rs 50 where as 7 pencils and 5 pens together cost Rs 46 . Find the cost of pencils and that of one pen .
As shown by graphically
please answer fast

Answer 1

5x +7y = 50 ; 7x +5y = 46 ; x=3 ,y=5

Answer 2

let cost of pen be x and that of pencil be y
5x+7y=50 ...(1)
7y+5x=46...(2)
adding equations (1) and (2)
12x+12y=96
dividing the result we got by 12
x+y=8...(3)
Subtracting equations (1) and (2)
x-y=-4...(4)
Adding equations (3) and (4)
(x+y=8)+(x-y=-4)
2x=4
x=2
substituting value of x in equation (4)
x-y=-4
2-y=-4
2+4=y
y=6
thus cost of 1 pen is 2rs and cost of one pencil is 6rs
hope it was helpful