Question

the cost of 5 pencils and 7pens together is 50 wheras cost of 7 pencils and 5 pens is 46 represent yhos algebrcally and geometrically​

Answer 1

Answer:

Step-by-step explanation:

5x+7y=50

x=50-7y/5(equation 1)

7x+5y=46

x=46-5y/7(equation 2)

sub. 1 in 2

50-7y/5=46-5y/7

y=5

x=46-5y/7

 =3

Answer 2

Let cost of pencil be Rs. x

Cost of pens be Rs. y

5 pencils and 7 pens together cost Rs. 50,

So we get

5x+7y=50

Subtract 7y both side we get

5x=50–7y

Divide by 5 we get

 

x=10−57y

Plug value of y which is factor of 5 to get whole number so plug y=5,10,15 we get

fory=5

x=10−57y=10−7=3

for y=10

x=10−57y=10−14=−4

fory=15

x=10−57y=10−21=−11

Therefore, the required points are (3,5),(−4,10),(−11,15).

Given that 7 pencils and 5 pens together cost Rs. 46

7x+5y=46

Subtract 7x both side we get

5y=46–7x

Divide by 5 we get

y=9.2–1.4x

Plug x=0,2,4 we get

for x=0

y=9.2-0 =9.2

for x=2

y = 9.2-2.8 =6.4

Therefore, the required points are

(0,9.2) (2,6.4) (4,3.6)

The graph is as shown above:

Since the point of intersection is (3,5),

Hence, the cost of one pencil is Rs. 3 and the cost of one pen is Rs. 5