Answer:
<em>4 pounds of ingredients are used in each batch.</em>
Step-by-step explanation:
Amount of flour = 
Amount of butter = 8 pounds
Amount of sugar = 
So, the <u>total amount of all ingredients</u> will be: 
Given that, she makes 12 batches of cookies using all the ingredients.
Thus, the amount of ingredients used in each batch 
X(x + 3) + 34 = (x + 5)(x + 2)
First, expand to remove parentheses.
Second, add '2x + 5x' to get '7x'.
Third, cancel out '

' on both sides.
Fourth, subtract '3x' from both sides.
Fifth, subtract '7x - 3x' to get '4x'.
Sixth, subtract '10' from both sides.
Seventh, subtract '34 - 10' to get '24'.
Eighth, divide both sides by '4', leaving the 'x' by itself.
Ninth, since '24 ÷ 4 = 6', simplify the fraction to '6'.
Tenth, switch your sides to get the answer.

Answer:
x = 6
The correct answer is: [B]: " y = 9 " .
_____________________________________________
Answer:
$34
Step-by-step explanation:
I'd work backwards.
For the third book, she paid all her remaining money. The problem says she paid "1/2 her leftover money + $3". This means that: (let m = money used to buy book 3)
m = 1/2m + 3
1/2m = 3
m = 6
For the second book: (let n = money before book 2)
n - m (money left after book 2) = 1/2n + 2
1/2n +2 is money used up for book, which is the same as n-m.
n = 1/2n + 2 + m
1/2n = 2 + m = 2 + 6
1/2n =8
n = 16
For the first book, she spent 1/2 her money + 1. If o = money before book 1 (or the whole allowance):
o - n = 1/2o + 1
o = 1/2o + n + 1 = 1/2o + 16 + 1
1/2o = 17
o = 34
Check!
Spent 17 (half 34) + 1 on book 1
16 left
Spent 8 (half 16) +2 on book 2
6 left
Spent 3 (half 6) + 3 on book 3
0 left