Question

evaluate x^3+y^3+z^-3xyz when x =-2,y=andz=3

Answer 1

${x}^{3} + {y}^{3} + {z}^{3} - 3xyz = (x + y + z)( {x}^{2} + y {}^{2} + z ^{2} - 2 xy - 2yz - 2xz)$
=(-2+3+3)(4+9+9+12-18+12)
=(4)(4+24)
=4×28
=112