a/ 2130-(x+130)+72=-64
\(2130-\left(x+130\right)=-64-72\) \(2130-\left(x+130\right)=-136\)\(x+130=2130+136\)\(x+130=2266\)\(x=2266-130\)\(x=2136\)vậy x=2136
a/ 2130-(x+130)+72=-64
<=> -x-130+72+2130=-64
<=> x=2130+72-130+64=2136
b/135-|9-x|=35
<=> |9-x|=135-35=100
<=> \(\left[\begin{array}{nghiempt}9-x=100\\9-x=-100\end{array}\right.\)
<=>\(\left[\begin{array}{nghiempt}x=-91\\x=109\end{array}\right.\)
c/10-|x+3|=-4-(-10)
<=> |x+3|=10+4+(-10)
<=>|x+3|=4
<=>\(\left[\begin{array}{nghiempt}x+3=4\\x+3=-4\end{array}\right.\)
<=>\(\left[\begin{array}{nghiempt}x=1\\x=-7\end{array}\right.\)
c/10-|x+3|=-4-(-10)
\(10-\left|x+3\right|=6\)\(\left|x+3\right|=10-6\)\(\left|x+3\right|=4\)\(\Rightarrow\left[\begin{array}{nghiempt}x+3=4\\x+3=-4\end{array}\right.\Leftrightarrow\left[\begin{array}{nghiempt}x=4-3\\x=-4-3\end{array}\right.\Leftrightarrow\left[\begin{array}{nghiempt}x=1\\x=-7\end{array}\right.\)
b/135-|9-x|=35
\(\left|9-x\right|=135-35\)\(\left|9-x\right|=100\)\(\Rightarrow\left[\begin{array}{nghiempt}9-x=100\\9-x=-100\end{array}\right.\Leftrightarrow\nghiempt{\left[\begin{array}{nghiempt}x=9-100\\x=9+100\end{array}\right.}\Leftrightarrow\left[\begin{array}{nghiempt}x=-91\\x=109\end{array}\right.\)
