(-4/5)*(-3/8)*(5/12) =3/10*5/12=1/8
(-25/44)*63/100*22/45+7/40= -63/176*22/45+7/40= -7/72+7/40= -(35+63)/360= - 28/360= -7/90
1) (26,9-x)*8,1=0
217,89-8,1х=0
8,1х=217,89-0
8,1х=217,89
х=217,89:8,1
х=26,9
2) -76,3*(x-6)=0
-76,3х+457,8=0
-76,3х=0-457,8
-76,3х= -457,8
х= -457,8:(-76,3)
х=6
3) (12,3+x)*10=0
123+10х=0
10х=0-123
10х= -123
х= -123:10
х= -12,3