if x+y+z=9 & x²+y²+z²=35, find x³+y³+z³-3xyz
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Answer:
The answer is 108..
x+y+z = 9
x²+y²+z²=35
(x+y+z)² = x²+y²+z²+2xy+2zx+2yz
--> 9² = 35+2(xy+yz+zx)
--> 81-35 = 2(xy+yz+zx)
--> 46/2 = (xy+yz+zx)
--> -23 = -xy-yz-zx
So, with the equation,
x³+y³+z³-3xyz
Let's expand the equation and distribute its exponential powers,,
= (x+y+z)(x²+y²+z² -xy-yz-zx)
= 9*(35-23)
= 9*12
= 108
Hope it helped you..
Thank you !!
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