Answer:

For this case we know that
represent the radius,
the height and the rate given is:


And replacing we got:

And that represent 
Step-by-step explanation:
For a tank similar to a cylinder the volume is given by:

For this case we know that
represent the radius,
the height and the rate given is:

For this case we want to find the rate of change of the water level when h =6m so then we can derivate the formula for the volume and we got:

And solving for
we got:

We need to convert the rate given into m^3/min and we got:

And replacing we got:

And that represent 
Step-by-step explanation:
multiply it
x²-3x+3x-9=0
x²-9=0
x²=9
square root both side we get
x=3
Answer:
-8
Step-by-step explanation:
substitute x with 3
-4(3) + 4
simplify (multiply)
-12+4
simplify
-8
Answer:
2a
Step-by-step explanation:
We can combine like terms.
There are 2 'a' s in the expression, so we can rewrite a + a as 2a.
x+y = -19
x*y = 35
x=-19-y
(-19-y)y = 35
y^2 +19y +35 = 0
y = -2.066965626
therefore x=35/y = -16.93303437