Answer:
C. (x + 4)(x + 5).
Step-by-step explanation:
We need 2 numbers whose product is + 20 and whose sum is + 9.
They are + 5 and + 4 , so
x2 + 9x +20
= (x + 4)(x + 5).
The complete table will be:

<u><em>Explanation</em></u>
Suppose, the number of sit-ups in Sunday is 
Mean is the simple average of some numbers. <u>For finding the mean number</u> of sit-ups per day, we need to <u>divide the 'total number of sit-ups' by the 'total number of days'</u>.
Here the total number of days is 7 and the total number of sit-ups for 7 days 
Given that, the mean number of sit-ups per day is 100. So, the equation will be...

So, the number of sit-ups you have to do Sunday is 175.
Answer: x < -3 or x > 5
Step-by-step explanation: Interval notation shows the values of x. X is less than -3, or greater than 5.
X2=9 has only one solution, which is 4.5
30 should be the correct answer