\(\Rightarrow12+20x-60=45x-15\Leftrightarrow25x=-33\Leftrightarrow x=-\dfrac{33}{25}\)
12+20x−60=45x−15
25x=−33
x=−\(\dfrac{33}{25}\)
\(\dfrac{3+5x}{5}-3=\dfrac{9x-3}{4}\)
\(\Leftrightarrow\dfrac{5x-12}{5}=\dfrac{9x-3}{4}\)
\(\Leftrightarrow20x-48=45x-15\)
\(\Leftrightarrow25x=-33\)
\(\Leftrightarrow x=-\dfrac{33}{25}\)