1)(1/2)⁻⁷-75·5⁻²=2⁷-75/25=128-3=125;
2)(2/3)⁻⁴·32-(0.2)⁻³=(3/2)⁴·2⁵-(1/0.2)³=3⁴·2-5³=162-125=37;
3)25²·(-5)⁻⁵+1.2·(1/6)⁻²=5⁴·(-5)⁻⁵+1.2·6²=(-5)⁴⁻⁵ +0.2·6·6²=(-5)⁻¹+0.2·6³=
=(-1/5)+0.2·216=-0.2+43.2=43
4)(-1²/₃)³·(1/3)⁻⁴-0.8·2⁻³=(-5/3)³·3⁴-8·0.1·2⁻³=(-5)³·3⁴⁻³-2³⁻³·0.1=
=(-5)³·3-0.1=(-375)-0.1=-375.1