The revenue, in dollars, of a company that produces video game systems can be modeled by the expression 5x2 + 2x – 80. the cost, in dollars, of producing the video game systems can be modeled by 5x2 – x + 100, where x is the number of video game systems sold. if profit is the difference between the revenue and the cost, what expression represents the profit?
profit can be modeled by the polynomial expression .
if 1,000 video game systems are sold, the company’s profit is $ .

SALES:      5x² + 2x – 80
- COST:      5x² – x + 100
=                
PROFIT:      0x²+3x-180                        
(+3x because we subtracted a negative (-x), which is called adding, similarly taking away 100 from negative 80 is -180.)

Checking:
5x² + 2x – 80
5(500)²+2(500)-80 = 1,250,920

5x² – x + 100
5(500)² – (500) + 100= 1,249,600

Profit = 1,250,920 - 1,249,600 = 1,320
 
0(500)²+3(500)-180 = 1,320  YAY! {:-)

Double Checking:

5x² + 2x – 80
5(5000)²+2(5000)-80 = 125,009,920

5x² – x + 100
5(5000)² – (5000) + 100= 124,995,100

Profit = 125,009,920 - 124,995,100 = 14,820
 
0(5000)²+3(5000)-180 = 14,820  YAY! {:-)