15a =6a - 90
Move all the numbers with variables to one side
15a - (6a) = 6a -(6a) -90
9a = -90
9a/9 = -90/9
a = -9
Hope this helps
Answer:

Step-by-step explanation:
HOPE THAT THIS IS HELPFUL.
HAVE A GREAT DAY.
Okay so you take the number of weekdays to the number of weekends the ratio is 5:2 one month, which usually has 30 days which is 4 weeks tops so that is about 21 week days and and 9 weekends then times both by 12 you get 108 weekends and 252 weekdays i know that only equals 360 but this is a rough estimate so write that as a fraction 3/7 so there is a third that it will be on a weekday
Answer:
the diameter is 28 centimeters and the area is 97.4 centimeters
Step-by-step explanation:
the diameter is just the radius plus the radius so its 28
and i just solved for the area and got 97.4