Question

if sum of two number is 14 and difference is 8 then find the number

Answer 1

$\bold{here \: is \: your \: answer}$

According to 1 st condition...
$x + y = 14$
Now , according to the 2 nd Condition,
$x - y = 8$
According to the given condition,
Sum of these two..
$x + y = 14 \\+ x - y = 8$
________
$2x = 22 \\ x = 11$

$x - y = 8 \\ 11 - y = 8 \\ y = 11 - 8\\ y = 3$
The two numbers are
x = 11
y = 3
__________________________________
This is the answer.
Hope it helps you.

Answer 2

Let the numbers be x and y
ATP
x+y=14 this is equation 1
x-y=8 this is equation 2
Solving equation 1 and 2
x+y=14
x-y=8
Therefore y is cut so value of x is 22
Putting value of x in equation 1 we get
22+y=14
therefore y=14-22
so y=-8
therefore x=22and y=-8