13) \(720\div\left[41-\left(2x-5\right)\right]=2^3.5\)
\(\Rightarrow720\div\left[41-\left(2x-5\right)\right]=40\)
\(\Rightarrow41-\left(2x-5\right)=720\div40\)
\(\Rightarrow41-\left(2x-5\right)=18\)
\(\Rightarrow2x-5=41-18\)
\(\Rightarrow2x-5=23\)
\(\Rightarrow2x=23+5\)
\(\Rightarrow2x=28\)
\(\Rightarrow x=28\div2\)
\(\Rightarrow x=14\)
14) \(\left\{\left[\left(2x+14\right)\div2^2-3\right]\div2\right\}-1=0\)
\(\left[\left(2x+14\right)\div2^2-3\right]\div2=0+1\)
\(\left[\left(2x+14\right)\div2^2-3\right]\div2=1\)
\(\left(2x+14\right)\div2^2-3=1.2\)
\(\left(2x+14\right)\div2^2-3=2\)
\(\left(2x+14\right)\div2^2=2+3\)
\(\left(2x+14\right)\div2^2=5\)
\(2x+14=5.2^2\)
\(2x+14=20\)
\(2x=20-14\)
\(2x=6\)
\(x=6\div2\)
\(x=3\)
