You have not given us any of the steps that Ricardo took to simplify the
expression, and you also haven't given us the list of choices that includes
the description of his mistake, so you're batting O for two so far.
Other than those minor details, the question is intriguing, and it certainly
draws me in.
If Ricardo made a mistake in simplifying that expression, I'm going to say that
it was most likely in the process of removing the parentheses in the middle.
Now you understand that this is all guess-work, because of all the stuff that you
left out when you copied the question, but I think he probably forgot that the 3x
operates on everything inside the parentheses.
He probably wrote that 3x (x-3) is
either 3x² - 3
or x - 9x .
In reality, when properly simplified,
3x (x - 3) = 3x² - 9x .
Answer:
5.20 to the nearest hundredth.
Step-by-step explanation:
The altitude line bisects the base of the triangle to form 2 right angled triangles with hypotenuse = 6 and the base = 3.
So, by the Pythagoras theorem the altitude is calculated as follows:
6^2 = 3^2 + x^2
x^2 = 36 - 9 = 27
x = √27
= 5.20 to the nearest hundredth.
The solution is in parenthesis, so this means the numbers are included in the answer. Since the first number is 2, 2 is a possible answer so the circle at positive two would be solid.
The other solution is infinity, so the answers are any number to the right of the 2 on the number line.
This makes the answer: A solid circle appears at positive 2. The number line is shaded between positive 2 and positive 5.
