Question

If x + y = 4 and x2 + y2 = 7, then the value of xy is -
(A) 1
(B) 9/2
(C) 1/4
(D) 3/4​

Answer 1

Answer:

I think the value of xy is 1

Answer 2

Formula Used : (x + y)² = x² + y² + 2xy

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(x + y)² = x² + y² + 2xy

Substitute the Values

⇒ (4)² = 7 + 2xy

⇒ 16 = 7 + 2xy

⇒ 16 - 7 = 2xy

⇒ 9 = 2xy

⇒ 9/2 = xy