a: \(65\cdot48+35\cdot48+12\cdot58-12\cdot38\)
\(=48\left(65+35\right)+12\left(58-38\right)\)
\(=48\cdot100+12\cdot20\)
\(=4800+240=5040\)
b: \(2018^2+\left\{15^2:\left[175-\left(2^3\cdot5^2-6\cdot25\right)\right]\right\}\)
\(=1+\left\{\dfrac{225}{175-\left(8\cdot25-150\right)}\right\}\)
\(=1+\dfrac{225}{175-\left(200-150\right)}\)
\(=1+\dfrac{225}{175-50}=1+\dfrac{225}{125}=1+\dfrac{5}{3}=\dfrac{8}{3}\)