Answer:
x
Step-by-step explanation:
-2x²(x – 5) + x(2x² – 10x) + x
The simplest for of the above equation can be obtained as follow:
-2x²(x – 5) + x(2x² – 10x) + x
Rearrange
x(2x² – 10x) – 2x²(x – 5) + x
Factorise
x.2x(x – 5) – 2x²(x – 5) + x
2x²(x – 5) – 2x²(x – 5) + x
Carry out the minus (–) operation
=> x
Therefore, the simplest form of expressing -2x2(x – 5) + x(2x2 – 10x) + x is x.
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: A reasonable estimate of the minimum is 20.
Well, there are 3 feet in a yard so you can just divide the number of yards by 3.