Answer:
b
Step-by-step explanation:
The equation (form) is: 
The solution of the equation is: 
Explanation:
First, let's call the number we are going to solve for "x".
Then two thirds of this number can be written as:
Then "plus 4" means add 4 we get:
"is 7" means that the above expression is equal to 7 (as follows):
The solution of the above equation is:
Answer:
The answer is C/Point E
Step-by-step explanation:
I did the test.
Yes it is a natural number
T(t)=e−kt(∫ekt[KM(t)+H(t)+U(t)]dt+C)
M is the outside temperature, H is other things that affect temperature
in the tank(0 in this case), and U is the solar panel. K comes from the
time constant, and should be the inverse of the time constant I believe.
T is temperature, t is time.
T(t)=e−164t(∫e164t[164(80)+4t]dt
After integrating I keep getting
−16304+256t+Ce−164t
I calculate C to be 16414 setting t equal to 0 and using the initial conditions
