-2*0.3= -0.6;
-0.3*-5/6= 3/10*5/6= 3*5/10*6=15/60=1/4=0,25;
-2 в 5 степени= -2*2*2*2*2=-32;
-4,2*0,2=-8,4;
-0,7*-2/21=7/10*2/21=7*2/10*21=6/30=1/5=0,2;
-3 в 4 степени= -3*3*3*3=-243.
2) (4,3-3у)-2(5,8+у)=4,3-3у-11,6-2у=-7,3-5у;
(3,8-5х)-3(2,4-х)=3,8-5х-7,2+3х=-3,4-2х.
3)1 1/3*(-3/4)-(-2 1/7)*1 2/5= 4/3*(-3/4) - (-15/7)*7/5=
= -12/12 +15*7/7*5= -1+3=2;
(-11 1/4)*(-1/9) - 4 7/12* 4/11 = 45/4*1/9 - 55/12*4/11=
5/4 - 5/3 =15/12- 20/12=-5/12