Answer:
M=a2-a1/b2-b1
Step-by-step explanation:
-3-a/-2-1
-4a/3
/-4/-4
a=3/-4
how do i answer that I don't even know that sorry
Answer:

Step-by-step explanation:
Circumference of the column 
Circumference of a circle
Therefore:

Area of a Circle 
Since radius of the cross section of the column =9 meters
Area of the cross section of the column

Answer:I think it's 3 7.75/20 hours
Step-by-step explanation:
Multiply 2/15 by 20 (2x20 and 15x20)
Then 13/20 by 15 (13x15 and 20x15)
Subtract (195/300 - 40/300)
And you get 155/300
Then divide by 20 because dividing by 15 gives you 10.333333
So divide 155/300 by 20 (155÷20 and 300÷20)
And you get 7.75/20
Finally subtract the 2 hours from 5 hours and get 3 hours
Your answer is 3 7.75 hours