Answer: Hello mate!
you know that the equation is (or at least i think this is):
p(t) = 800 + 9t/90 + t^2
You want to know the "rate of change" after 6 hours.
We know that the rate of change is the derivative of P(t) with respect to t; this is
now we want the rate of change when t = 6, then we replace t by 6 in the derivate equation:
so the rate of change after 6 hours is 12.9
where 
If the equation is wrong ( because you write P(t) = 800 1 + 9t 90 + t2, and i don really know how to iterprete it) tellme and we can do the derivate again :D
X = 2a - b²
x - 2a = b²
√x-2a = b
Just to clarify, all of x-2a is under the square root.
That's my answer Brainliest me!
294 gallons of oil is the answer because you do 42 and mltiply it by 7
The annual return percentages will be evaluated using the formula:
A=P(1+r/100)^n
where:
A=amount
P=principle
r=rate
n=time
a] A=$500, P=$400, n=1 years
500=400(1+r)^1
solving for r we shall obtain:
1.25=1+r
hence
r=1.25-1
r==0.25
annual rate of investment is 25%
b] A=2500+100=$2600, P=$ 2000, n=1 year
hence
2600=2000(1+r)^1
2600/2000=1+r
1.3=1+r
r=1.3-1
r=0.3
annual rate of investment is 30%
