1)1/7*х+1/14=0
1/7х = -1/14
x = -1/14 : 1/7
x = -1/14 * 7/1
x= -1/2
2)1/25-1/100*х=0
1/100x=1/25
x=1/25: 1/100
x = 1/25 * 100 /1
x = 4
3)17*(5+х)-20*х=8*х-14
85+17x-20x=8x-14
-3x-8x=-14-85
-11x=-99
x=9
4)1+7*(15-3*х)-(2*х+48)=-34*(5-х)+18*(1-2*х)
1+105-21x-2x-48=-170+34x+18-36x
58-23x=-152-2x
-23x+2x=152-58
-21x=200
x=200/(-21)
x=-9 11/21