Let x represent the cost of book B
Book A: $17.50
Book B: x
Sales tax: (A + B) x 6% = .06(17.50 + x) = 1.05 + .06x
book A + book B + sales tax = total cost
(17.50) + (x) + (1.05 + .06x) = 44.52 <em>plugged in all of the values</em>
18.55 + 1.06x = 44.52 <em>added like terms</em>
1.06x = 25.97 <em>subtracted 18.55 from both sides</em>
x = 24.50 divided 1.06 from both sides
Answer: $24.50
Based on the calculations, the unknown number is equal to 
- Let the unknown number be x.
<h3>How to find an
unknown number:</h3>
Translate the word problem into an algebraic expression, we have;
Adding 21 to the unknown number:

Multiplying the result by 3:

84 more than two-thirds of the unknown number:

Equating the equations, we have:

Cross-multiplying, we have:

Read more on word problems here: brainly.com/question/13170908
Answer:
Volume of block Jennifer bought:
V = side^3 = 12 x 12 x 12 = 1728 (in3)
Volume of sphere Jennifer wanted to make:
V = (4/3) x pi x radius^3 = (4/3) x pi x (4/2)^3 = 33.5 (in3)
a, The number of spheres she can make:
N = 1728/33.5 = 51.58 = ~51
b, The area of remaining clay after she made a sphere:
A = 1728 - 33.5 = 1694.5 (in3)
Hope this helps!
:)
The volume of this figure is 660 cube centimetre