<u><em>Answer:</em></u>
c = 4
<u><em>Explanation:</em></u>
The number of solutions for any equation is equal to the degree of the equation.
The given equation is a second degree equation which means that it has two solutions.
The only possible way for it to have one unique real solution is that the two <u>solutions are equal</u>
<u>This means that:</u>
x - 4 = x - c
<u>Now, we solve for c:</u>
x - 4 - x = x - c - x
-4 = -c
c = 4
Hope this helps :)
Answer:

Step-by-step explanation:
The GCF doesn't have to be a number. In this case, it is -y because both the -2xy and -9y share it. It's also easier when you take out a negative. Once you take the GCF out, your new expression should be:

Answer:
60 square units
Step-by-step explanation: