So the book guy mark downed the price of the books by 46%, also known as 0.46. All decimals are less than 1. So then, what you do is you take b, which is the variable defining the price of the book, then you multiply it by 0.46. So the answer of b would be b x 0.46. For C, you must do 29 x 0.54, and that will give you the answer for C. Finally, in D, take the answer you got in C, and subtract that by 29. This will give you your 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
-48 plugging in everything and using PEMDAS it should be -48
Amanda Billy
1st week 10 5
2nd week 20 10
3rd week 30 20
4th week 40 40
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A) Amanda's method is linear because the number of minutes increased by an equal number every week.</span>
common difference is 10.
1st week 0 + 10 = 10
2nd week 10 + 10 = 20
3rd week 20 + 10 = 30
4th week 30 + 10 = 40
Billy's method is exponential:
5(2)^x
1st week 5(2⁰) = 5(1) = 5
2nd week 5(2¹) = 5(2) = 10
3rd week 5(2²) = 5(4) = 20
4th week 5(2³) = 5(8) = 40