Question

d) Solve: x + y = 4; 2x - 5y = 1​

Answer 1

Answer:

Given-

x + y = 4

x= 4 - y. _______(1)

putting the value of x from (1) in the above equation, we get.

2(4 - y) - 5y = 1

8 - 7y = 1

7y = 8 - 1

7y = 7

y = 1

putting the value of on y in (1), we get

x = 4 - y

x = 4 - 1

x = 3

therefore x =3 and y=1

Answer 2

Answer:

$x + y = 4 \: \: \: \: \: \: (1)$

$2x - 5y = 1 \: \: \: \: \: \: (2)$

From(1) we have

$x = 4 - y$

Putting this value of x in (2)

$2(4 - y) - 5y = 1$

$8 - 2y - 5y = 1$

$8 - 7y = 1$

$8 - 1 = 7y$

$7 = 7y$

$y = 1$

Putting the value of yin (1) we have

$x + 1 = 4$

$x = 3$

Thus,

(x, y) =(3, 1)