Answer:
see the explanation
Step-by-step explanation:
<em><u>The question is </u></em>
Identify the domain and the range, using words and inequalities
Let
x -----> the number of kilowatt-hours (kWh) of electricity per month
y ----> the price per month
we know that
Part 1) For the value of x between 0 kWh and 400 kWh

The price is equal to

therefore
The domain is the interval ------> [0,400)
The domain is all real numbers greater than or equal to 0 kWh and less than 400 kWh
The range is ($30)
The range is equal to $30
Part 2) For the value of x equal to 400 kWh or more per month

The domain is the interval -----> [400, infinite)
The domain is all real numbers greater than or equal to 400 kWh
The price is

<em>Find the range</em>
For x=400 kWh

so

The range is the interval -----> [38.8, infinite)
To calculate the square root, you can either use the √symbol on a calculator or you can manually find it using Prime Factorization. For non-perfect squares, Prime Factorization is the way to go.
The first two steps work for solving large perfect squares as well.
1. Divide your number into perfect square factors.
2. Take the square roots of your perfect square factors.
3. If your number doesn't factor perfectly, reduce your answer to simplest terms.
4. If needed, estimate. In some cases if you have memorized some of the square roots, you can estimate where the number would be.
ie.

you know that

and

, so you can estimate that the

would be between 7 and 8 but closer to 8.
5. <span>Alternatively, reduce your number to its lowest common factors as your first step.</span><span> Finding perfect square factors isn't necessary if you can easily determine a number's prime factors (factors that are also prime numbers).
ie. </span>

=

=

=

Hope this helped!!!
Answer would be 70m squared
Slope intercept form is y = mx + b.
Y = coordinate y.
M = Slope
X = coordinate x.
B = y-intercept.
Slope formula: (y2-y1) / (x2-x1)
Plug in: (-1 - 7) / (4 - 2) = -4.
We can just insert the pair (2,7) as our x and y to solve b.
7 = -4(2) + b.
Solve for b.
7 = -8 + b.
-b = -8 -7
-b = -15
b = 15.
Original equation:
y = mx + b
y = -4x + 15
Answer:
Rate of change of the diameter is equal to 0.053cm/min
Step-by-step explanation:
A snowball is of the shape of a sphere
Surface area of Sphere (S)= 
Rate of change of surface area
dS/dt = -4
the negative sign indicates the surface area is decreasing.
Radius = d/2 where d represents diameter
using this is the surface area equation
S = 
= 
dS/dt = 2*pi*d*d(d)/dt
4 = 2*pi*d*(d)/dt
d(d)/dt = 2/12*pi=
cm/min
so the rate of change of the diameter is equal to 0.053cm/min