\(A)9-25=\left(7-x\right)-\left(25+7\right)\)
\(\Rightarrow9-25=7-x-25-7\)
\(\Rightarrow x=7-25-7-9+25\)
\(\Rightarrow x=\left(7-7\right)+\left(25-25\right)-9\)
\(\Rightarrow x=0+0-9\)
\(x=-9\)
\(B)x-\left(17-x\right)=x-7\)
\(\Rightarrow x-17+x=x-7\)
\(\Rightarrow2x-17=x-7\)
\(\Rightarrow x=-7+17\)
\(x=10\)