Пошаговое объяснение:
a) (3a-1/3b)³= (3a)³-3(3a)²*(1/3b)+3*3a*(1/3b)²-(1/3b)³=
= 27a³ - 27a²*1/3b + 9a*1/9b² - 1/27b³= =27a³ - 9a²b + ab² - b³/27;
б) (-2-1/4x)³=-(2+1/4x)³= -(2³+3*2²*1/4x +3*2(1/4x)²+(1/4x)³)=
= -(8+3x+6/16x²+1/64x³) = -8 -3x -3x²/8 -x³/64;
в) (-10x-5)²=-(10x+5)²= -(100x²+ 2*10x*5 +25)= -100x²-100x-25.
