Question

If x + y = 5 and xy = 4, find x - y using indentities.​

Answer 1

Answer:

3

Step-by-step explanation:

(x-y)^2 = x^2+y^2-2xy

x-y = root of x^2+y^2-2xy

we can write x^2+y^2 as (x+y)^2 - 2xy

x-y = root of (x+y)^2 - 4xy

we know that x+y =5 and xy =4

x-y = root of 25 -16

root of 9=3