Đáp án:
a) x=3
Giải thích các bước giải:
\(\begin{array}{l}
a)\left( {\dfrac{{x - 3}}{5} + 1} \right):4 = \left( {\dfrac{{2x}}{3} - \dfrac{1}{2}} \right):6\\
\to \left( {\dfrac{{x - 3 + 5}}{5}} \right).\dfrac{1}{4} = \left( {\dfrac{{4x - 3}}{6}} \right).\dfrac{1}{6}\\
\to \dfrac{{x + 2}}{{20}} = \dfrac{{4x - 3}}{{36}}\\
\to 36x + 72 = 80x - 60\\
\to 44x = 132\\
\to x = 3\\
b)\left( {5x + \dfrac{{x + 2}}{2}} \right):9 - x = \left( {\dfrac{{x + 3}}{5} + 15} \right):12 - 2\\
\to \dfrac{{10x + x + 2}}{2}.\dfrac{1}{9} - x = \dfrac{{x + 3 + 75}}{5}.\dfrac{1}{{12}} - 2\\
\to \dfrac{{11x + 2}}{{18}} - x = \dfrac{{x + 78}}{{60}} - 2\\
\to \dfrac{{11x + 2 - 18x}}{{18}} = \dfrac{{x + 78 - 120}}{{60}}\\
\to \dfrac{{2 - 6x}}{{18}} = \dfrac{{x - 42}}{{60}}\\
\to 120 - 360x = 18x - 756\\
\to 378x = 876\\
\to x = \dfrac{{146}}{{63}}
\end{array}\)
