4/5t+4/15+2/3t=1
4/5t+2/3t=1-4\15
12\15t+10\15t=15\15-4\15
22\15t=11\15
t=11\15:22\15
t=11\15*15\22
t=1/2
1.(х+45)-15=34
х+45-15=34
х=34-45+15
х=4
2.(х-56)-24=17
х-56-24=17
х=17+56+24
х=97
3.(х-27)+35=81
х-27+35=81
х=82+27-35
х=74
4.478-(256+х)=427
478-256-х=427
-х=427-478+256
х=205
5.791-(х-298)=683
791-х+298=683
-х=683-791-298
х=406