Answer:
g(3) = 5
Step-by-step explanation:
Look at the picture
-11b-4-(-b+3)
goes to -11b-4+b-3
=-10b-7
The number of bacteria in species A at time t is given by:

.
The number of bacteria in species B at time t is given by

You are asked to find N(t) which is the difference in the species at time t. Difference refers to the answer is a subtraction problem. Thus, we are asked to find N(t) = A(t)-B(t)
We subtract and obtain:

That is,

which is the last answer choice.
With respect to notation, it is common to denote an exponent using ^. So if we want to write

we can write "(.25t)^3"
Simplifying
3[x + -1] = 12
Reorder the terms:
3[-1 + x] = 12
[-1 * 3 + x * 3] = 12
[-3 + 3x] = 12
Solving
-3 + 3x = 12
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '3' to each side of the equation.
-3 + 3 + 3x = 12 + 3
Combine like terms: -3 + 3 = 0
0 + 3x = 12 + 3
3x = 12 + 3
Combine like terms: 12 + 3 = 15
3x = 15
Divide each side by '3'.
x = 5
Simplifying
x = 5