`x + 4005 = 5400`
`x = 5400 - 4005`
`x = 1395`
`----------`
`x : 8 = 5420`
`x = 5420 xx 8`
`x = 43360`
`-----------`
`3 xx x = 6966`
`x = 6966 : 3`
`x = 2322`
\(a,x=5400-4005\\ x=1395\\ b,x=5420.8\\ x=43360\\ d,x=6966:3\\ x=2322\)
a: x=5400-4005=1395
b: x=5420x8=43360
c:x=6966:3=2322
x = 5400 - 4005
x = 1395
x = 5420 . 8
x = 43360
x = 6966 : 3
x = 2322
\(x+4005=5400\\ x=5400-4005\\ x=\text{1395}\\ \\ x:8=5420\\ x=5420\text{×}8\\ x=43360\\ \\ 3\text{ }\text{×}x=6966\\ x=6966:3\\ x=2322\)