SOLUTION: the value of expression x^2 + y^2 + z^2 -xy -yz- zx ,if x= 97 ,y =98 , z=99

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Question 731473: the value of expression x^2 + y^2 + z^2 -xy -yz- zx ,if x= 97 ,y =98 , z=99
Found 2 solutions by MathLover1, lokesh mishra:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
the value of expression x%5E2+%2B+y%5E2+%2B+z%5E2+-xy+-yz-+zx ,if x=+97 ,y+=98+, z=99 will be

97%5E2+%2B+98%5E2+%2B+99%5E2+-97%2A98+-98%2A99-+99%2A97

=9409+%2B+9604+%2B+9801+-9506+-9702-+9603
=9409+%2B+9604+%2B+9801+-%289506+%2B9702%2B+9603%29
=28814+-28811
=3

Answer by lokesh mishra(5) About Me  (Show Source):
You can put this solution on YOUR website!
x^2 + y^2 + z^2 -xy - yz- zx = 1/2{(x-y)^2 + (y-z)^2 + (z-x)^2 }
= 1/2{(97-98)^2 + (98-99)^2 + (99-97)^2 } = 1/2 ( 1 + 1 + 4 ) = 6/2 = 3