a)\(2.x-18=10\)
\(\Rightarrow2.x=10+18=28\)
\(\Rightarrow x=28:2=14\)
Vậy: \(x=14\)
b)\(5.\left(7.x-15\right)-75=25\)
\(\Rightarrow5.\left(7.x-15\right)=75+25=100\)
\(\Rightarrow7.x-15=100:5=20\)
\(\Rightarrow7.x=20+15=35\)
\(\Rightarrow x=35:7=5\)
Vậy: \(x=5\)