Question

x^2+y^2 = 58 ,xy =21 ,x+y=?

Answer 1

Solution :

Given that,

x² + y² = 58, xy = 21, x + y = ?

We know that,

(x + y)² = x² + y² + 2xy

Putting the given values, We get

(x + y)² = 58 + 2×(21)

(x + y)² = 58 + 42

(x + y)² = 100

⇒ (x + y) = √( 100 )

⇒ x + y = ± 10