a)
{-4(a+2b-4c-\frac{1}{2}d+\frac{1}{8}m)=-4a-8b+16c+\frac{4}{2}d-\frac{4}{8}m=-4a-8b+16c+2d-0,5m}
b)
{-\frac{2}{5}(10x-20y+0,5z-25)=-\frac{2}{\not5^1}\cdot \not10^2x+\frac{2}{\not5^1}\cdot \not20^4y-\frac{\not2^1}{5}\cdot \frac{1}{\not2^1}z+\frac{2}{\not5^1}\cdot \not25^5=}
=-2\cdot 2x+2\cdot 4y-\frac{1}{5}z+10=-4x+8y-0,2z+10
d)
(20x-15y+\frac{2}{3}z-\frac{5}{6}p)\cdot (-0,3)=
=20x\cdot (-0,3)-15y\cdot (-0,3) +\frac{2}{3}z\cdot (-0,3)-\frac{5}{6}p\cdot (-0,3)=
=-6x+4,5y-\frac{\not2^1}{\not3^1}z\cdot \frac{\not3^1}{\not10^5}+\frac{\not5^1}{\not6^2}p\cdot \frac{\not3^1}{\not10^2}=
=-6x+4,5y-\frac{1}{5}z+\frac{1}{4}p=
=-6x+4,5y-0,2z+0,25p