Answer:
x = 12
Step-by-step explanation:
In similarity triangles angles are congruent.
∠D = ∠A
x² - 8x = 48
x² - 8x - 48 = 0
x² + 4x - 12x - 48 = 0
x(x + 4) - 12(x + 4) = 0
(x +4)(x - 12) = 0
x - 12 = 0 {Ignore x + 4 = 0, as measurements won't have negative values}
x = 12
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 .
Let number of books by astrid's = x
Out of x , 84% are fiction.
So, Number of non fictional books = x - 
= 
→Ratio of number of books to fictional books
⇒[Dividing numerator and denominator by 4.]
→Out of 25 books by astrid 21 are fictional.
→ Number of fictional books by astrid = 
The answer is 38 over 100 cups. Simplified = 19 over 50. All you do to get the answer is put 38 over 100. Then divide 38 by 2. Then divide 100 by 2.
