Ответ:
Объяснение:a^3+27b^3/a+3b=(a^3+(3b)^3)/(a+3b)=(a+3b)(a^2-3ab+b^2)/(a+3b)=a^2-3ab+b^2
<span>cos4x cos2x + sin4x sin2x =0
cos(4x-2x)=0
cos2x=0
2x= pi/2 + pi*n, n</span>∈Z
x=pi/4 + (pi*n)/2 , n<span>∈Z</span>
(1/3)^-10*(1/3)^3=((1/3)^-7)/((1/3)^-5)=(1/3)^-2=9