how do i do this word problem?

Question

i dont know how to do this problem here it is:

a bicycle maker sold 300 bicycles last year at a profit of $300 each. The maker wants to increase the profit margin this year, but predicts that each $20 increase profit will reduce the number of bicycles sold by ten. How many $20 increases in profit can the maker add in and expect to make a total profit of $100,000?

if someone can solve it step by step and give explanations it would be more than appreciated

Answer 1

The profit for each bicycle is 300 + 20x, because it starts at $300 and goes up by $20 for each $20 increase in price; x is the number of $20 price increases. The number of bicycles sold is 300 - 10x, because each $20 price increase reduces sales by 10. The total profit is therefore (300 + 20x)(300 - 10x), the product of profit and number of bicycles sold. You need to solve for this expression equal to 100000. First, expand the product. Then set it equal to 100000 and rearrange it to get a polynomial function equal to zero. Finally, use any technique for quadratic equations to solve for x. You'll probably get two values, but one will be negative, which wouldn't make sense, so the other one is your correct answer.

Answer 2

you do 300 bicycles multiplied by $300 this shows that at 300 dollars a piece and 300 sold the years profit is 90 000 dollars. Every time you subtract 10 bikes from the bikes sold part you add 20 dollars per each bike.
so i did: 290bikes X $320=92 800
280bikes X $340=95 200
270bikes X $360=97 200
260bikes X $380=98 800
250bikes X $400=100 000

Therefore you would need to increase the price per each bike by 20 dollars 5 times before reaching a yearly profit of $100 000