The answer is C: 3 books, 2.5 weeks.
Answer:
......................................,........
B. (k+10f)(k-5f) you can tell in 2 ways. 1. if the second sign is neg then the signs in the factors are going to be one neg and one positive so that knocks out C and D. Then you look at the second term and since the 5 is positive then the 10 has to be positive so you end up with a positive 5kf.
The second way is to FOIL them out. When you check B you get

combine your like terms and you have your original expression of

Hope that helps
The picture in the attached figure
we know that
<span>The construction shown is an angle bisector
m<XAB=m<CAX
</span>so
m<BAC=2*[m<XAB]-----> 2*32°----->m<BAC= 64°
the answer ism<BAC=64°
1 gallon of milk is the better deal. A gallon is 4 quarts, so for 2 quarts, it would be left. I hope I helped!