If x+y=5 and xy=4 find x-y

1.	If x+y=5 and xy=4 find x-y
Answer» (x+y)2\xa0= x2\xa0- 2xy + y2= x2\xa0+ 2xy + y2\xa0- 4xy\xa0= (x+y)2\xa0- 4xy\xa0= 52\xa0- 4\xa0× 4\xa0= 25 - 16 = 9∴ x - y = √9\xa0= 3

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