-(x-3-84) = (x +70 -71) -6
-(x-87) = ( x - 1)-6
-x + 87= x - 7
-2x = -94
x=47
\(-\left(x-3-84\right)=\left(x+70-71\right)-6\)
\(\Rightarrow-x+3+84=x+70-71-6\)
\(\Rightarrow-x-x=70-71-6-3-84\)
\(\Rightarrow-2x=-94\)
\(\Rightarrow x=-94:\left(-2\right)\)
\(\Rightarrow x=-47\)