<h2>Numerical expressions are numbers and signs, like below. The following are some examples of numerical expressions, numerical expressions do not use letters.
4 + 20 – 7, (2 + 3) – 7, (6 × 2) ÷ 20, 5 ÷ (20 × 3)
An algebraic expression uses letters and it says you to find "x/y/z".
Example;
4+20xy-7x, (2x+3) - 7y+20.</h2>
Answer:
Domain: (+∞, -∞)
Step-by-step explanation:
Domain = x value
hope it helps
Answer:

Step-by-step explanation:
<u>Mathematical Modeling</u>
To model a real-life situation, a mathematical model can be constructed in such a way it accurately represents the variables measured in the system.
This problem requires to build a model for the yearly cost of a small and successful business.
The first data is the fixed monthly cost or the money the owner must pay regardless of the number of employees he hires. This cost includes shipping supplies and products for $2,000. To operate for a full year, the fixed cost is 12*$2,000=$24,000.
The other component of the cost function is the variable cost of x employees. Given each employee costs $1,600 each month, having x employees cost 1,600x each month. For a full year, the variable cost will be
12*1,600x=19,200x.
We finally form the total cost function:

To find the perpendicular line a y- 2 = 7/3 (x + 5) you must first observe that the slope is m = 7/3, therefore, the slope of the perpendicular line put of the reciprocal, that is, m = - 3/7. So the possible options are A or C, but since the point (-4, 9) must go through the line, we find that the equation that satisfies that is option C.Therefore the perpendicular line that passes through the point (-4, 9) is C. y - 9 = -3/7 (x + 4)