3x-5(12-6x)=-8,5
3х-60+30х=-8,5
33х=-8,5+60
33х=51,5
х=51 1/2:33=103/2*1/33=1 37/66
-12-2,3*(6,5-7x)=13,2
-12-14,95+16,1х=13,2
16,1х=40,15
х=40,15:16,1= 40 15/100:16 1/10=(4015*10)/100*161=4015/1610=2 795/1610=2 159/322
8*(2x-5)=12,3x-68
16х-40=12,3х-68
3,7х=-28
х=-28:3 7/10=-28*10/37=-280/37=-7 21/37