\(\left[124-\left(20-4x\right)\right]:30=4\)
\(\left[124-\left(20-4x\right)\right]=120\)
\(\left(20-4x\right)=124-120\)
\(\left(20-4x\right)=4\)
\(4x=20-4\)
\(4x=16\)
\(x=4\)
\(\left[124-\left(20-4x\right)\right]=120\)
\(20-4x=124-120=4\)
\(4x=20-4=16\)
\(x=16:4=4\)
vậy x=4
\(\left[124-\left(20-4x\right)\right]:30=4\)
\(124-\left(20-4x\right)=120\)
\(20-4x=4\)
\(4x=16\)
Vậy \(x=4\)
\(\left[124-\left(20-4x\right)\right]:30=4\)
\(\left[124-\left(20-4x\right)\right]=4\times30\)
\(124-\left(20-4x\right)=120\)
\(\left(20-4x\right)=124-120\)
\(20-4x=4\)
\(4x=20-4\)
\(4x=16\)
\(x=16:4\)
\(x=4\)
