Answer:
6 days
Step-by-step explanation:
pay 60 = -60
Let d = the number of days
30d - 60 = sister
20d = me
Equation:
30d - 60 = 20d           Move 30 to the other side
-30d      -30d
-60 = 20d - 30d           Combine liked terms
-60 = -10d                Â
-10 Â Â -10 Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Divide
d = 6