a.
\(35.18-5.7.28=35.18-35.28\)
\(=35\left(18-28\right)=35.\left(-10\right)=-350\)
b.
\(45-5.\left(12+9\right)=45-5.12-5.9\)
\(=45-60-45=-60\)
c.
\(24.\left(16-5\right)-16.\left(24-5\right)=24.16-24.5-16.24+16.5\)
\(=-24.5+16.5=5\left(-24+16\right)=5.\left(-8\right)=-40\)