Question

7. If x+y=5 and x.y=4, find x-y using identities.
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Answer 1

Step-by-step explanation:

x+y = 5

xy = 4

4xy = 16

x^2+2xy+y^2 = 25

x^2–4xy+2xy+y^2 = 25–16 = 9

x^2–2xy+y^2 = 9

(x-y)^2 = 3^2, or

x-y = ±3.

Answer 2

Answer:

x=1 then y=4

x=4 then y=1