Ответ:

1)1/3х+4=0; 1/3х=-4; х=-4:1/3; х= -12

2)23х+20(1,6-х)=-1; 23х+32-20х= -1

23х-20х=-32-1; 3х=-33: х= -11

3)3х+7=0; 3х= -7; х=-7/3; х=-2 1/3

4)7х-4=х-16; 7х-х=-16+4; 6х=-12; х=-2

5)6х-(2-3х)=16; 6х-2+3х=16; 6х+3х=16+2; 9х=18; х=2

6)5(х+3)=8(10-х); 5х+15=80-8х; 5х+8х=80-15;

13х=65; х=5