\(\left(-x+31\right)-39=69+11\Leftrightarrow-x+31-39=80\)
\(\Leftrightarrow\) \(-x=80+39-31=88\) \(\Leftrightarrow\) \(x=-88\) vậy \(x=-88\)
\(\left(-x+31\right)-39=69+11\)
\(\Leftrightarrow\left(-x+31\right)-39=80\)
\(\Leftrightarrow-x+31=80+39\)
\(\Leftrightarrow-x+31=119\)
\(\Leftrightarrow-x=119-31\)
\(\Leftrightarrow-x=88\Rightarrow x=-88\)
( -x + 31 ) - 39 = 69 + 11
( -x + 31 ) - 39 = 80
( -x + 31 ) = 80 + 39
-x + 31 = 119
-x = 119 - 31
-x = 88
x = -88
(-x+31)-39=69+11
-x+31=69+11+39
-x+31=119
-x=119-31
-x=88
\(\Rightarrow\)x=-88