b) \(PT\Leftrightarrow-4u+6u-u-3u=-3-24+27\)
\(\Leftrightarrow-2u=0\)
\(\Leftrightarrow u=0\)
Vậy: \(S=\left\{0\right\}\)
e) \(PT\Leftrightarrow0,1-t+0,2=2t-1-0,7\)
\(\Leftrightarrow3t=2\)
\(\Leftrightarrow t=\dfrac{2}{3}\)
Vậy: \(S=\left\{\dfrac{2}{3}\right\}\)
d) \(PT\Leftrightarrow-3+4x=2x-15\Leftrightarrow2x=-12\Leftrightarrow x=-6\)
Vậy: \(S=\left\{-6\right\}\)
f) \(PT\Leftrightarrow3x-5=2x\Leftrightarrow x=5\)
Vậy: \(S=\left\{5\right\}\)