\(125-\left(-75\right)+32-\left(48+32\right)\)
\(=125-\left(-75\right)+32-80\)
\(=125+75+32-80\)
\(=200+32-80\)
\(=232-80\)
\(=152\)
\(-63+415-37-115\)
\(=352-57-115\)
\(=315-115\)
\(=200\)
\(13.\left(-2\right)^2+37.4+4.\left(-150\right)\)
\(=13.2^2+37.4+4.-150\)
\(=13.4+37.4+4.-150\)
\(=4.\left(13+37+-150\right)\)
\(=4.-100\)
\(=-400\)
\(-15.x+4=79\)
\(\Leftrightarrow-15.x=79-4\)
\(\Leftrightarrow-15.x=75\)
\(\Leftrightarrow x=75:-15\)
\(\Leftrightarrow x=-5\)
Vậy \(x=-5\)
\(15-\left(2+x\right)=23\)
\(\Leftrightarrow2+x=15-23\)
\(\Leftrightarrow2+x=-8\)
\(\Leftrightarrow x=-8-2\)
\(\Leftrightarrow x=-10\)
Vậy \(x=-10\)
\(\left(x+2\right)\left(x^2-1\right)=0\)
\(\Leftrightarrow\left(x+2\right)\left(x^2-1^2\right)=0\)
\(\Leftrightarrow\left(x+2\right)\left(x+1\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left(x+1\right)\left(x-1\right)=0\)
\(\Leftrightarrow x=\pm1\)
Vậy \(x\in\left\{\pm1\right\}\)
\(56:\left|x-4\right|=7\)
\(\Leftrightarrow\left|x-4\right|=56:7\)
\(\Leftrightarrow\left|x-4\right|=8\)
\(\Leftrightarrow\orbr{\begin{cases}x-4=8\\x-4=-8\end{cases}\Leftrightarrow\orbr{\begin{cases}x=8+4\\x=-8+4\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=12\\x=-4\end{cases}}}\)
Vậy \(x\in\left\{12;-4\right\}\)
