If x-y=12 and xy=25/4,find x+y

As (x+y) 2

= x2+ 2xy+y2

=x2 - 2xy +y2 +4xy

= (x- y)2+4xy

=( 12 )2+ 4* 25/4

= 144+25= 169 = 132

Therefore, x+y = 13

  • 7
What are you looking for?