Question

If x ^2 + y ^2= 9 and xy = 8, then x + y is equal to

Answer 1

Answer:

x² + y² = 9

=> (x + y)² - 2xy = 9

=> (x+y)² -2 × 8 = 9

=> ( x + y)² = 9 + 16 = 25

=> x + y = √25

=> x + y = 5

Answer 2

The value of x + y is equal to 5.

Step-by-step explanation:

Given,

$x^2 +y^2=9$ and xy = 8

To find, the value of (x + y) = ?

∴ $(x+y)^{2} =x^{2} +y^{2} +2xy$

Put $x^2 +y^2=9$ and xy = 8, we get

⇒ $(x+y)^{2}$ = 9 + 2(8)

⇒ $(x+y)^{2}$ = 9 + 16

⇒ $(x+y)^{2}$ = 25 = $5^{2}$

⇒ x + y = 5

∴ The value of x + y = 5

Thus, the value of x + y is equal to 5.