Răspuns :
Explicație:
A=primul nr
B=al doilea nr
A-B=70
A:B =8rest7
A=B×8+7
B=|----|
A=|----|----|----|----|----|----|----|----|__+7
7p=70-7=63
1p=63:7=9
B=9
A=9×8+7
A=79
V:79-9=70
79:9=8 rest7
a |__|__|__|__|__|__|__|__| +7 |
b |__|<= 70 =>
70 = 7s + 7
70 - 7 = 7s
63 = 7s
1s = 63 : 7
1s = 9 (a)
8s + 7 = 8×9 + 7 = 72 + 7 = 79 (b)