\(1,x+3.2=10\\ \Rightarrow x+6=10\\ \Rightarrow x=10-6=4\\ 2,8.3-x=20\\ \Rightarrow24-x=20\\ \Rightarrow x=24-20=4\\ 3,\left(x+100\right).4=800\\ \Rightarrow x+100=800:4\\ \Rightarrow x+100=200\\ \Rightarrow x=200-100=100\\ 4,\left(x-120\right):35=5\\ \Rightarrow x-120=5\times35\\ \Rightarrow x-120=175\\ \Rightarrow x=175+120=295\\ 5,5x+10=25\\ \Rightarrow5x=25-10\\ \Rightarrow5x=15\\ \Rightarrow x=15:5=3\\ 6,18-3x=0\\ \Rightarrow3x=18\\ \Rightarrow x=18:3=6\\\)
\(7,45-\left(x-3\right)=5\\ \Rightarrow45-x+3=5\\ \Rightarrow48-x=5\\ \Rightarrow x=48-5=43\\ 8,78+5x-16=67\\ \Rightarrow62+5x=67\\ \Rightarrow5x=67-62\\ \Rightarrow5x=5\\ \Rightarrow x=5:5=1\\ 9,40-3x+5=15\\ \Rightarrow45-3x=15\\ \Rightarrow3x=45-15\\ \Rightarrow3x=30\\ \Rightarrow x=30:3=10\\ 10,\left(x-3\right)\left(x-5\right)=0\\ \Rightarrow\left[{}\begin{matrix}x-3=0\\x-5=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=3\\x=5\end{matrix}\right.\)
