Explicație pas cu pas:
1. a) 503-127-205+189-64=
=376-205+189-64
=171+189-64
=360-64
=296
21189+16347-20508=
=37536-20508
=17028
b) 185*25*36:15:20=
=4625*36:15:20
=166500:15:20
=11100:20
=555
895:5*36:9*29=
=179*36:9*29
=6444:9*29
= 716*29
= 20764
c) 26+360:(3*50*5:750)=
=26+360:(150*5:750)
=26+360:(750:750)
=26+360:1
=26+360
=386
105-2*[11+5*3-(4+8)]=
= 105-2*(11+15-12)
=105-2*(26-12)
=105-2*14
=105-28
=77
d)[(609:3+72:3)*3-75*8]*2=
=[(203+24)*3-600]*2
=(227*3-600)*2
=(681-600)*2
=81*2
=162
3*[90:45+2*(69:13+10)]+105:3=
!! aici cred că este o greșeală 69:13 nu da un număr natural.