2.4x(20+3/5)+33.1x7.6
=2.4×20.6+33.1×(10-2.4)
=33.1×10+2.4×20.6-2.4×33.1
=331-2.4×(33.1-20.6)
=331-0.3×8×12.5
=331-0.3×100
=331-30
=301
2.4x(20+3/5)+33.1x7.6
=2.4×20.6+33.1×(10-2.4)
=33.1×10+2.4×20.6-2.4×33.1
=331-2.4×(33.1-20.6)
=331-0.3×8×12.5
=331-0.3×100
=331-30
=301