if x+y=5 and xy=4 find the value of x-y
Given: x + y= 5, xy= 4
To Find: Value of (x-y)
Sol:
Using identity, (x+y)²= x² + y² +2xy
(5)² = x² + y² +2(4)
25= x² + y² +8
x² + y² = 17.
Using Identity, (x-y)² = x² + y² -2xy
(x-y)² = 17- 2(4)
(x-y)² = 17-8
(x-y)² = 9
(x-y)= ±3
Therefore, The value of (x-y) is ±3.
Regards,