Question

If x + y = 5, xy = 4 then x² + y2 = ?
x + y = 5, xy = 4 eaus x2 + y2 = ?​

Answer 1

Answer:

if x+y = 5 & xy = 4

now

(x+y)² = x²+2xy+y² (on squaring both sides)

(5)² = x² + 2×(4) + y² ( on putting the values of x+y & xy )

25 = x²+8+y²

x²+y² = 25–8

x²+y² = 17

now ,

(x-y)² = x² - 2xy + y²

(x-y)² = (x²+y²) - 2xy

on putting the values of x²+y² & xy

(x-y)² = 17 - 2(4)

(x-y)² = 17–8

(x-y)² = 9

(x-y) = √9

(x-y) = 3 ANSWER

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Step-by-step explanation: