\(\left[\left(6.x-72\right):2-84\right]\times28=5628\)
\(\left(6.x-72\right):2-84=5628:28\)
\(\left(6.x-72\right):2-84=201\)
\(\left(6.x-72\right):2=201+84\)
\(\left(6.x-72\right):2=285\)
\(6.x-72=285\times2\)
\(6.x-72=570\)
\(6.x=570+72\)
\(6.x=642\)
\(x=107\)