Discussion

Explanation:

Given, x + y + z = 10
Squaring both sides, we get
⇒ x² + y² + z² + 2xy + 2yz + 2zx = 100
⇒ 30 + 2xy + 2yz + 2zx = 100
⇒ 2xy + 2yz + 2zx = 70
⇒ xy + yz + zx = 35

We know, x³ + y³ + z³ - 3xyz = (x + y + z)(x² + y² + z² - xy - yz - zx)

⇒ x³ + y³ + z³ - 3xyz = (10)(30 - 35)

⇒ x³ + y³ + z³ - 3xyz = (10)(-5)

⇒ x³ + y³ + z³ - 3xyz = -50

Hence, option (c).

» Your doubt will be displayed only after approval.