4)
5.4-2 1\3= 5 4\10-2 1\3=3+(2\5-1\3)=3+(2*3\15-1*5\15)=3+1\15=3 1\15
3 1\15:7 2\3=46\15: 23\3=46\15*3\23=2\5=0.4
5)
2 1\3+0.25=2 1\3+25\100=2 1\3+1\4=2 +(1*4\12+1*3\12)=2 7\12
2 7\12*0.12=31\12*12\100=31\100=0.31
6)
7.6-4 3\4=7 6\10-4 3\4=3+(3\5-3\4)=3+(3*4\20-3*5/20)=3-3\20=2 17\20
2 17\20:1.9=57\20:19\10=57\20*10\19=3\2=1 1\2=1.5
(1/2)*√(3Х+1) = 4
√(3Х+1) = 4*2/1 = 8
3Х+1 = 8²
3Х = 64-1 = 63
Х = 63/3 = 21.
Проверка (√(3Х+1))/2 = (√(21*3 +1))/2 = (√64)/2 = 8/2 = 4.
0,3x+0,8y+1,5x+1,2y=1,8x+2y