Реши 20 и 21

20. Вычислите:

а) \(6\frac13-8=-1\frac23\);
б) \(-2\frac27+4\frac35=2\frac{11}{35}\);
в) \(5\frac13-6\frac14=-\frac{11}{12}\);
г) \(\frac38:\left(-\frac9{16}\right)=-\frac23\);
д) \(\frac5{12}\cdot(-6)=-2\frac12\);
е) \(-3\frac29\cdot3=-9\frac23\);
ж) \(\frac47\cdot(-49)=-28\);
з) \(-16:\left(-\frac49\right)=36\);
и) \(-3\frac12\cdot\left(-1\frac37\right)=5\).

21.

\(1\%=0,01;\ 5\%=0,05;\ 7\%=0,07;\ 10\%=0,1;\)
\(20\%=0,2;\ 25\%=0,25;\ 36\%=0,36;\ 50\%=0,5;\)
\(75\%=0,75;\ 100\%=1;\ 138\%=1,38;\ 263\%=2,63;\)
\(0,2\%=0,002;\ 0,43\%=0,0043.\)