If x + y + z = 16 and xy + yz + zx = 75, what is the value of x² + y² + z²?
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Correct answer: A
Explanation
Has been given :
x + y + z = 16
xy + yz + zx = 75
According to the formula:
(x + y + z)² = x² + y² + z² + 2(xy + yz + zx)
16² = x² + y² + z² + 2(75)
256 = x² + y² + z² + 150
x² + y² + z² = 256 − 150= 106