Question

solue = x+y = 4 ;2x - 5y=1​

Answer 1

Given:

• x + y = 4 ----- [Equation 1]
• 2x - 5y = 1 ----- [Equation 2]

To find:

Value of x and y = ?

Solution:

From Equation 1,

y = 4 - x ----- [Equation 3]

Substitute this value of y in Equation 2

2x - 5y = 1

➝ 2x - 5(4 - x) = 1

➝ 2x - 20 + 5x = 1

➝ 7x - 20 = 1

➝ 7x = 1 + 20

➝ 7x = 21

➝ x = 21 ÷ 7

➝ x = 3

Now, putting the value of x in Equation 3,

y = 4 - x

⇒ y = 4 - 3

⇒ y = 1

So, the values of x and y are 3 and 1 respectively.

Answer 2

x+y=4 ___(1), 2x−5y=1__(2)

multiply eq. (1) by 2.

and then subtract eq. (2)

2x+2y=8

2x−5y=1

- + -

____________

7y=7

y=1

x+y=4

x+1=4

x=3