yg jawab dapat banyak poin.. di mohon pakai cara ini sifat komutarif asosiatif distributif

Jawaban:
3.100 + 15 + 405=(100 + 15) + 405
=115 + 405
=520.
4.(-35) + 145 + 80=(145 - 35) + 80
=110 + 80
=190.
5.117 + 323 + (-427)=(117 + 323) - 427
=440 - 427
=13.
6.15 × 11 × (-20)=(15 × 11) × (-20)
=165 × (-20)
=-3.300.
7.55 × 5 × 10=(55 × 5) × 10
=275 × 10
=2.750.
8.28 × (-10) × 20=(28 × (-10)) × 20
=-280 × 20
=-5.600.