原式
=35x(23+15x4+2)
=35x(23+60+2)
=35x85
=(30+5)x(80+5)
=30x80++30x5+5x80+5x5
=2400+150+400+25
=2400+400+150+25
=2800+175
=2975
35×23+15×4×35+35×2
=35x(23+15x4+2)
=35x(23+60+2)
=35x85
=(30+5)x(80+5)
=30x80++30x5+5x80+5x5
=2400+150+400+25
=2400+400+150+25
=2800+175
=2975