Answer:
Part A: after 9 days the radius of the algae would be 12.81mm so the domain is 9. you would plot the domain at (0,9)
Part B: the y-intercept (the 9) represents the amount of algae the experiment started off with.
Part C: the rate of change is 0.
Step-by-step explanation:
 
        
             
        
        
        
ANSWER
x = ±1 and y = -4. 
Either x = +1 or x = -1 will work
EXPLANATION
If -3 + ix²y and x² + y + 4i are complex conjugates, then one of them can be written in the form a + bi and the other in the form a - bi. In other words, between conjugates, the imaginary parts are same in absolute value but different in sign (b and -b). The real parts are the same
For -3 + ix²y
⇒ real part: -3
⇒ imaginary part: x²y
For x² + y + 4i
⇒ real part: x² + y (since x, y are real numbers)
⇒ imaginary part: 4
Therefore, for the two expressions to be conjugates, we must satisfy the two conditions. 
Condition 1: Imaginary parts are same in absolute value but different in sign. We can set the imaginary part of -3 + ix²y to be the negative imaginary part of x² + y + 4i so that the 
   x²y = -4 ... (I)
Condition 2: Real parts are the same
   x² + y = -3 ... (II)
We have a system of equations since both conditions must be satisfied
   x²y = -4 ... (I)
   x² + y = -3 ... (II)
We can rearrange equation (II) so that we have
   y = -3 - x² ... (II)
Substituting into equation (I)
   x²y = -4 ... (I)
   x²(-3 - x²) = -4
   -3x² - x⁴ = -4
   x⁴ + 3x² - 4 = 0
   (x² + 4)(x² - 1) = 0
   (x² + 4)(x-1)(x+1) = 0
Therefore, x = ±1. 
Leave alone (x² + 4) as it gives no real solutions.
Solve for y:
   y = -3 - x² ... (II)
   y = -3 - (±1)²
   y = -3 - 1
   y = -4
So x = ±1 and y = -4. We can confirm this results in conjugates by substituting into the expressions:
   -3 + ix²y 
   = -3 + i(±1)²(-4)
   = -3 - 4i
   x² + y + 4i
   = (±1)² - 4 + 4i
   = 1 - 4 + 4i
   = -3 + 4i
They result in conjugates
        
                    
             
        
        
        
Answer:
See attachment
Step-by-step explanation:
Isolate y in the first inequality:

Now, with both x and y inequalities found, graph it.
 
        
             
        
        
        
Answer:
9
Step-by-step explanation: