a) \(98\times376,9+376,9\times2-376,9+376,9=376,9\times\left(98+2-1+1\right)=376,9\times100=37690\)
b) \(60-26,75-13,25=60-\left(26,75+13,25\right)=60-40=20\)
c)
\(38,25-18,25+21,64-11,64+9,93=\left(38,25-18,25\right)+\left(21,64-11,64\right)+9,93=20+10+9,93=39,93\)
d) \(45,28+52,17-15,28-12,17=\left(45,28-15,28\right)+\left(52,17-12,17\right)=30+40=70\)