Question

7X+ 4y =64
. 4X+7Y=57
x+y=- ?​

Answer 1

Step-by-step explanation:

7x + 4y = 64_______(1)

7y + 4x = 57_______(2)

adding both equations

11x + 11y = 121

x + y = 11

Answer 2

The value of $x+y=11.$

Step-by-step explanation:

We have,

$7x+4y=64$         .....(1)

And,

$4x+7y=57$         .....(2)

To find, the value of $x+y=?$

Adding (1) and (2), we get

$(7x+4y)+(4x+7y)=64+57$

⇒ $7x+4y+4x+7y=121$

⇒ $11x+11y=121$

⇒ $11(x+y)=121$

⇒ $x+y=\dfrac{121}{11} =11$

Hence, the value of $x+y=11$.