2х+20=8х-10-2
6х=32
х=5 1/3
Проверка:
5(32/6*0,4+4)=2(4*32/6-5)-2
92/3=92/3
Cos31π/3 = Сos(30π + π/3) = Cosπ/3 = 1/2
1) 4целых4/9 = 40/9
1целая1/3 = 4/3
40/9+4/3=40/9+12/9=52/9
52/9*3/28=13/21
2) 1целая47/105 = 152/105
1целая13/75 = 88/75
152/105-88/75 = 760/525-616/525 = 144/525
144/525*25/24= 6/21
4² * 4∧⁻(3 2/3)= 4∧(2-2) = 4