(x-4)(x^2+4x+16)-x(x+4)(x-4)=x^3-64-x(x^2-16)=x^3-64-x^3-16x=-16x-64=-16(x+4)
При x=-1,
-16(-1+4)=-16*3=-48
X2-3x+9/(х+3)(х2-3х+9) - х2+18/х2+27=х2-3х+9-х2-18/(х+3)х2-3х+9)=-9-3х(х+3)(х2-3х+9)=
=-3(х+3)/(х+3)(х2-3х+9)= 3/х2-3х+9
18⁶/6⁷*3⁵=(6⁶ *3⁶)/6⁷*3⁵=6⁶⁻⁷*3⁶⁻⁵=6⁻¹*3¹=3¹/6¹=1/2