Question

(ii) x3+ y3+ z3 - 3xyz
if x is 4 , y is 3, and z is -2​

Answer 1

Answer:

$x = 4 \\ y = 3 \\ z = - 2 \\ \\ {x}^{3} + {y}^{3} + {z}^{3} - 3xyz \\ {4}^{3} + {3}^{3} + {( - 2)}^{3} - 3(4)(3)( - 2) \\ = 64 + 27 + ( - 8) - ( - 72) \\ = 64 + 27 - 8 + 72 \\ \boxed{ = \underline{ \underline{ \large \bf 155}}}$

Answer 2

Answer:

$x = 4 \\ y = 3 \\ z = - 2 \\ \\ {x}^{3} + {y}^{3} + {z}^{3} - 3(4)(3)( - 2) \\ {4}^{3} + {3}^{3} + { - 2}^{3} - 12 \times 3 \times ( - 2) \\ 64 + 27 + 8 - 36 \times ( - 2) \\ 64 + 27 + 8 - 72 \\ 79 - 72 \\ 7$