Question

If x + y = 15 and xy = 45, what is the value of x^2 + y^2​

Answer 1

Given:

• x + y = 15

• xy = 45

To find :

• x² + y²

Solution :

As we know that :

• x² + y² = ( x + y )² - 2xy

put the value .

=> x² + y² = (15)² - 2(45)

=> x² + y² = 225 - 90

=> x² + y² = 135 .

Answer 2

Step-by-step explanation:

GIVEN :

• x + y = 8
• xy = 15.

TO FIND

• what is the value of x^2 + y^2

SOLUTION :

we know that,

( x + y )²= x² + y² + 2xy

x² + y² = ( x + y )² - 2xy

= 8² - 2×15

= 64 - 30

x² + y² = 34.

RESULT :

x² + y²= 34