An algebraic expression is a phrase in mathematics that consists of numbers such as 1,2,3 and the like, variables which are represented with letters and operations like addition, multiplication, subtraction and division. It is usually used to represent a certain situation which would relate the variables involved. To write the algebraic expression for the problem statement above, we do as follows:
Let x = number of consoles to be bought
y = number of games to be bought
z = number of controllers to bebought
C = total cost of all
The total cost would be equal to the sum of the price multiplied by the number of consoles, games and controllers bought. We write the algebraic expression as follows,
C = 299x + 59.99y + 29.99z
The answer is: 5,614 square inches.
The explanation is shown below:
1. The gift on the bottom is a rectangular prism. To calculate its surface area, you must apply the following formula:
![SA=2[(l)(w)+(l)(h)+(h)(w)]](https://tex.z-dn.net/?f=SA%3D2%5B%28l%29%28w%29%2B%28l%29%28h%29%2B%28h%29%28w%29%5D)
Where 
is the length (20 inches), 
is the width (42 inches) and 
is the heigth (16 inches).
2. Substitute values:
![SA1=2[(20in)(42in)+(20in)(16in)+(16in)(42in)]=3,664in^{2](https://tex.z-dn.net/?f=SA1%3D2%5B%2820in%29%2842in%29%2B%2820in%29%2816in%29%2B%2816in%29%2842in%29%5D%3D3%2C664in%5E%7B2)
3. The surface area of the other gifts can be calculated with the formula for calculate the surface area of a cube:
Where 
is the side.
4. The surface area of the bigger cube is:
5. The surface area of the smaller cube is:
6. The total surface area (the combined surface area of the three gifts) is:
In order to do this you have to substitute b with 9 and get 3a+9=54, now subtract 9 from both sides to leave a by itself and get 3a=45, now divide 3 in both sides to leave a by itself and get a=15
Hope this helps
