3 1/12+4 11/15+1 3/5=3 1/12+4 11/15+1 9/15=3 1/12+5 20/15=3 1/12+5 4/3=
=3 1/12+6 1/3=3 1/12+6 4/12=9 5/12
А-20=4
а=20+4
а=24
-------------
24-20=4
24=24
(0.8x-3):0.3=(0.6x-8.4):-9
(0.8x-3)*-9=(0.6x-8.4)*0.3
-7.2x+27=0.18x-2.52
-7.2x-0.18x=-2.52-27
-7.38x=-29.52
x=4
Ответ: x=4
(58+х)-23 = 96 54-(х-19) = 35
х = 96-58+23 54+19-35 = х
х = 61 х = 38
(58+61)-23 = 96 54-(38-19) = 35