Question

find the value of x²+y²+z² when x + y+z=? and xy+ yz+ zx =2

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Answer 1

Answer:

Squaring both sides

(x+y+z)

2

=x

2

+y

2

+z

2

+2(xy+yz+zx)

we can substitute given values

(x+y+z)

2

=18+(2×9)

(x+y+z)

2

=36

(x+y+z)=6