53-8=(50+3)-(5+3)=(50-5)+(3-3)=45+0=45
53-8=(40+13)-8=40+(13-8)=40+5=45
54-23=(50+4)-(20+3)=(50-20)-(4-3)=30+1=31
54-23=(40+14)-(10+13)=(40-10)+(14-13)=30+1=31
81-6=(80+1)-(5+1)=(80-5)+(1-1)=75+0=75
81-6=(70+11)-6=70+(11-6)=70+5=75
7+6=7+(3+3)=(7+3)+3=10+3=13
Пошаговое объяснение:
53-8=(50+3)-(5+3)=(50-5)+(3-3)=45+0=45
53-8=(40+13)-8=40+(13-8)=40+5=45
54-23=(50+4)-(20+3)=(50-20)-(4-3)=30+1=31
54-23=(40+14)-(10+13)=(40-10)+(14-13)=30+1=31
81-6=(80+1)-(5+1)=(80-5)+(1-1)=75+0=75
81-6=(70+11)-6=70+(11-6)=70+5=75
7+6=7+(3+3)=(7+3)+3=10+3=13
Пошаговое объяснение: