The first blank on the left side should be 0 I think
The top 4 firms have (23 +22 +18 +12)% = 75% of the market.
The 4-firm concentration ratio is 0.75 or 75%.
is the polynomial of one variable with second-order and
is the polynomial of two variables with third-order
<h3>What is polynomial?</h3>
Polynomial is the combination of variables and constants in a systematic manner with "n" number of power in ascending or descending order.
We have polynomials:
and

For 
In this polynomial, the number of variables is one and the maximum power of x is 2, therefore:
This is the polynomial of one variable with second order.
In polynomial,
there are two variables x and y.
The maximum power of x is 3( x has a power of 2 and y has a power of 1)
This is the polynomial of two variables with third order.
Thus,
is the polynomial of one variable with second-order and
is the polynomial of two variables with third-order.
Learn more about Polynomial here:
brainly.com/question/17822016
Answer: For part A, the formula for the employee's pay is <em><u>P</u></em>ay = hourly <em><u>r</u></em>ate times <em><u>h</u></em>ours . P = r × h The equation is P = 13h To find how many hours are required to earn a given amount, fill in given values and solve for the missing variable . 7800 = 13h h= 7800/13 600 hours needed.
For part B, the formula for this employee's pay is <em><u>P</u></em>ay = <u><em>B</em></u>onus + hourly <em><u>r</u></em>ate times <em><u>h</u></em>ours . P = b + rh
330 = 90 + r(24) 330 - 90 = 24r . 240 = 24r 240/24 = r . r = 10
The employee's pay rate is $10 per hour.