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Answer: The first day the author reaches 100 days is on day 16.
To solve this problem, you could use a graphing calculator to graph the given equation. Then, determine when this line crosses 100. It crosses when x = 15.539. Therefore, we would have to round up to 16 so it is at least 100.
You could use the quadratic equation to solve: 100 = x^2 -12x + 45
Either you will get 16. If you use the quadratic formula, make sure to only use the positive answer.
To solve this problem, you could use a graphing calculator to graph the given equation. Then, determine when this line crosses 100. It crosses when x = 15.539. Therefore, we would have to round up to 16 so it is at least 100.
You could use the quadratic equation to solve: 100 = x^2 -12x + 45
Either you will get 16. If you use the quadratic formula, make sure to only use the positive answer.
Given the model,[tex]y = x^2-12x+45[/tex], the first day that at least 100 copies of the book were sold was the 16th day
The given equation is:
[tex]y = x^2-12x+45[/tex]
where the number of books sold is represented by y
The number of days after an award-winning author appeared at an autograph-signing reception is represented by x
The first day that at least 100 copies of the book were sold will be calculated as shown below:
[tex]x^2-12x+45 \geq 100\\\\x^2-12x+45-100\geq 0\\\\x^2-12x-55\geq 0\\\\[/tex]
Solving the quadratic inequality above
x ≥ -3.54 and x ≥ 15.54
Since the number of days cannot be negative, the only possible solution is
x ≥ 15.54
Also note that the day has to be a whole number
Therefore, the first day that at least 100 copies of the book were sold was the 16th day
Learn more here: https://brainly.com/question/20923849
