Answer:
Step-by-step explanation:
Let's say the Physics book costs $x
The Chemistry book will cost $x - $6
Two such Chemistry books will cost;
2($x - $6) = $(2x - 12)
Three such Physics books cost $3x
$(2x - 12) + $3x = $123
$5x - $12 = $123
$5x = $111
x = $22
So the Physics book costs; $22
and the Chemistry book costs $22
- 6 = $16
Answer:

Step-by-step explanation:
Let the side length of the square base =s feet
Let the height of the box = h
Given that the volume of the box = 
Volume of the box =
Then:

Surface Area of a Rectangular Prism =2(lb+bh+lh)
Since we have a square base, l=b=s feet
Therefore:
Surface Area of our closed box

Take the .5 of the 17.5 and convert it to a fractin.
we know .5 is equal to 50% or 1/2
now we have a mixed number

in order to convert it into an improper fraction you need to multiply the whole number by the denominator and then add the numerator all while keeping the denominator constant.

so
To find the missing dimension you will use the formula for finding the volume of a prism and solve for the missing dimension. In this case 2ft is how deep the pool is and you will solve for the width of the pool.
V = Bh, where B is the area of the base. In this case, use the area of a trapezoid formula.
286 = 1/2h(8 +13)2
<u>286</u> = <u>21h</u>
21 21
h = 13.6
The width of the wading pool is approximately 13.6 feet.
Answer:
5(7d-5)
Step-by-step explanation:
taking 5 common from 35d-25
= 5(7d- 5)