Answer:
1386cm^2.
Step-by-step explanation:
radius of circle=21cm
area of circle(a)=?
we know,
A=pi r^2
=22/7×(21)^2
=1386cm^2
Answer:
Option A.
and 
Step-by-step explanation:
we know that
The solution of the first inequality is the shaded area below the solid line 
The solid line passes through the points (0,4) and (3,0) (the y and x intercepts)
therefore
The first inequality is

The solution of the second inequality is the shaded area to the right of the solid line x=0
therefore
The second inequality is

A. $40, because you would do 1,000 × 1.04 = $1,040, and then subtract the original $1,000.
b. $81.60, because 1,000 × 1.04² = 1,081.6
c. $480.24, because 1,000 × 1.04^10 = 1,480.24.
I have used the formula for compound interest presuming you were aware of it, but I will be happy to explain what I did if you want :).
I hope this helps!
Answer:
The base (b) has to be positive and different of 1. The logarithm is the inverse of exponential, so:
logb(a) = x ⇒ a = bˣ
So, for b = 0 ⇒ 0ˣ = a
And there is impossible, "a" only could be 0.
For b = 1 ⇒ 1ˣ = a
And the same thing would happen, the logarithming would be to be 1, and the function will be extremally restricted.
For b<0, then the expression a = bˣ will be also restricted, and will not represent all values of a.
So, 0<b<1 and b >1.