a: Ta có: \(\left(x-7\right)\times22=\left(5\times x\right)+33\)

=>22x-154=5x+33

=>22x-5x=154+33

=>17x=187

=>x=11

b: TA có: \(7,75-\left(0,5\times x:5-6,2\right)=5\)

=>\(0,1\times x-6,2=7,75-5=2,75\)

=>\(0,1\times x=6,2+2,75=8,95\)

=>x=8,95:0,1=89,5

c: \(7:\left(3,8\times x-\frac{57}{19}+3\right)=1,75\)

=>\(7:\left(3,8\times x\right)=1,75\)

=>\(3,8\times x=7:1,75=4\)

=>\(x=\frac{4}{3,8}=\frac{20}{19}\)

\(7:\left(\frac{3,8\times x-57}{19}+3\right)=1,75\)

=> \(\frac{3,8\times x-57}{19}+3=7:1,75\)

=> \(\frac{3,8\times x-57}{19}+3=4\)

=> \(\frac{3,8\times x-57}{19}=4-3=1\)

=> \(3,8\times x-57=19\)

=> \(3,8\times x=19+57=76\)

=> \(x=76:3,8=20\)

Vậy x = 20.

\(7:\frac{5.8.x-57}{19+3}=7.\frac{22}{40x-57}=1775\)

<=> \(\frac{154}{40x-57}=1775=>x=\frac{154+1775.57}{40}\)

\(72:x=20\)

      \(x=72:20\)

      \(x=3,6\)

\(57:x=3,8\)

      \(x=57:3,8\)

      \(x=15\)

\(24:x=4,8\)

      \(x=24:4,8\)

      \(x=5\)

\(x\times10=8,5\)

           \(x=8,5:10\)

           \(x=0,85\)

72 : \(\chi\) = 20

\(\chi\)        = 72 : 20 

\(\chi\)        = 3,6

57 :\(\chi\) = 3,8

     \(\chi\)  = 57 : 3,8

     \(\chi\)   = 15

24 :\(\chi\) = 4,8

      \(\chi\) = 24 : 4,8

      \(\chi\) = 5

\(\chi\)x 10 = 8,5

\(\chi\)       = 8,5 : 10

\(\chi\)       = 0,85