Six tenths, one half, two fifths
1: 80% The reason why is because if you do 4/5, you get .80, move the decimals to places to the right, and you get 80%
2: 95% Process of Elimination, and Educated Guess.
3: 33 1/3% If you do 50/150, you get 0.33333... Like I said, move the decimal point two places to the right, and you get 33.33...%
<em>I hope this helps, and Happy Holidays! :)</em>
All you have to do, is combine like terms. Let's go through it:

Arrange it so you can easily combine like terms:

So, your answer for the sum is 1) 7x² - 10x + 2
One dozen eggs is 48 eggs. Altogether that costs 40 dollars. If six of the eggs were broken then the money wasted would be 5 dollars.
The reason that it is 5 dollars is becuase it takes 10 to buy 12 eggs, and half of that is 6. So divide both 12 and 10 (separately) and you get 5 dollars for 6 eggs.
To get the percent you must divide 5 by 40.
The answer comes out to about 12.5% or 0.125.
So in the end, 12.5% of the money was wasted due to the broken eggs.
Hope this helped!