Question

Question in attachment.

Answer 1

Hi ,

x + y + z = 0

x = - ( y + z )

x² = ( y + z )²


x² = y² + z² + 2yz

x² - 2yz = y² + z² ---( 1 )

Now ,

( x² + y² + z² ) / ( x² - yz )

= ( x² + x² - 2yz ) / ( x² - yz ) [ from ( 1 ) ]

= ( 2x² - 2yz ) / ( x² - yz )

= [ 2 ( x² - yz ) ]/ ( x² - yz )

= 2

option ( 3 ) is correct.

I hope this helps you.

:)

Answer 2

Heya Lipi ^_^

--> x + y + z = 0
=> x² + y² + z² + 2xy + 2yz + 2xz = 0
=> x² + y² + z² + 2yz + 2x [ y + z ] = 0
=> x² + y² + z² + 2yz + 2x [ -x ] = 0
=> x² + y² + z² = 2x² - 2yz
=> [ ( x² + y² + z² ) / ( x² - yz ) ] = 2  

--> We're done ... ^_^ Hope you're satisfied with the answer