11 x (X-6)=4 x X +11
=> 11 x X - 11 x 6=4 x X +11
=> 11 x X - 66 = 4 x X+11
=> 11 x X - 4 x X = 11+66
=> (11-4) x X = 77
=> 7 x X=77
=> X=77:7
=> X=11
`1xx(x-6)=4xx x+11`
`11 xx x-11 xx 6=4xx x+11`
`11×x−66=4×x+11`
`11×x−4×x=11+66`
`(11−4)×x=77`
`7×x=77`
`x=11`
Vậy `x=11`