Question

plzz solve this sum
the chapter name is -pair of linear equation in two variables

Answer 1

Let the age of Rajan be x,
Age of Jay be y.

x : y = 3 : 2

2x = 3y .
2x - 3y = 0 [ Equation 1 ]

After five years,
Age of rajan = x + 5
Age of Jay = y + 5 .

Given,
x+ 5 : y + 5 = 4 : 3

3x + 15 = 4y + 20

3x - 4y = 5 . [Equation 2 ]

Multiplying Equation ( 1 ) by 3 and Equation (2) by 2 .

6x - 9y = 0
6x - 8y = 10 ( Subtracting both equations)
==========
-y = -10
y = 10

Now, 2x - 3(10) = 0 , 2x = 30 , x = 15 .

Therefore ,Age of Rajan is 15 and Jay is 10 at present.

Answer 2

$Hey \: There$!!

Let x and y are the present ages of Rajan and Jay respectively.

A.T.Q.
x : y = 3 : 2
x / y = 3 / 2
2x = 3y
2x – 3y = 0 .....(1)

After five years,
Rajan's age = (x + 5) years
Jay's age = (y + 5) years

Now, A.T.Q.
x + 5 : y + 5 = 4 : 3
(x + 5) / (y + 5) = 4 / 3
3(x + 5) = 4(y + 5)
3x + 15 = 4y + 20
3x – 4y + 15 – 20 = 0
3x – 4y – 5 = 0 .....(2)

Multiplying (1) by 3 and (2) by 2 and then subtracting
6x – 9y = 0
6x – 8y = 10
_________
– y = – 10
y = 10

Substituting y = 10 in (1)
2x – 3 (10) = 0
2x – 30 = 0
2x = 30
x = 30 / 2
x = 15

Thus, present ages of Rajan and Jay are 15 and 10 years respectively.
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