Amber plus 2 family members = 3 total people on the plan.
They share the minutes equally so divide the minutes by 3 to find how many she can use:
720 / 3 = 240 minutes per month.
Now divide the monthly minutes by 30 days:
240 / 30 = 8 minutes per day.
m=6
this is because m=n=6 since the triangle is an equilateral triangle
hope it helps:)))
This problem can be simplified by remembering that since

, we have

. Then we have

.
Umm. i am not sure if this will help but, i would pick the first one. mainly because, i like to think of it as money, like for example. If i had two separate banks, and in both of them i had seven dollars. If i give seven dollars to a charity and there is nothing left in my bank, i would add my other money from my second bank into my first one. that way i will have money in the bank i would normally go to.