You have the right idea that things need to get multiplied.
What should be done is that the entire fraction needs to get multipled by the lowest common denominator of both denominators.
Let's look at the complex numerator. Its denominators are 5 and x + 6. Nothing is common with these, so both pieces are needed.
The complex denominator has x - 3 as its denominator. With nothing in common between it and the complex numerator, that piece is needed.
So we multiply the entire complex fraction by (5)(x + 6)(x -3).
Numerator: 
= (x+6)(x-3) - (5)(5)(x-3)
= (x+6)(x-3) - 25(x-3)
= (x-3)(x + 6 - 25) <--- by group factoring the common x - 3
= (x -3)(x - 19)
Denominator: 

Now we put the pieces together.
Our fraction simplies to (x - 3) (x - 19) / 125 (x + 6)
 
        
             
        
        
        
I think if I did it right it should be B
 
        
                    
             
        
        
        
Answer:
a) Here we have:
"In Family A, the youngest child is 7 years younger than the oldest, who is 18"
Let's define:
Y = age of the youngest child.
O = age of the oldest child.
Then we know that:
Y = O - 7
O = 18
Then we can replace the second equation into the first one:
Y = 18 - 7 = 11.
b) Here we have:
"In Family B, the middle child is 5 years older than the youngest child."
Let's define:
Y = age of the youngest child.
M = age of the middle child.
Here we have only one equation:
M = Y + 5.
 
        
             
        
        
        
Answer:
<em>The least number of items to produce is 41</em>
Step-by-step explanation:
<u>Average Cost</u>
Given C(x) as the cost function to produce x items. The average cost is:

The cost function is:

And the average cost function is:

We are required to find the least number of items that can be produced so the average cost is less or equal to $21.
We set the inequality:

Multiplying by x:

Note we multiplied by x and did not flip the inequality sign because its value cannot be negative.
Adding 20x:


Swapping sides and changing the sign:

Dividing by 41:

The least number of items to produce is 41