Respuesta :

Answer:

Well the digits in my answer will always end in a 0 or  always be in the tens.

Step-by-step explanation:

50-10=40, 50+10=60

20-10=10, 20+10=30

30-10=20,30+10=40

40-10=30,40+10=50

60-10=50,60+10=70