1.-28×-28×-28+13×13×13+16×16×16
=21,952+2,197+4,096
=28,245.
2.12×12×12+-7×-7×-7+-5×-5×-5
=1,728+-343+-125
=1,260
D 2520 -------------------------------------------
Answer:
b. 58%
Step-by-step explanation:
Calculate the area of the entire rectangle using the formula A = lw.
The lowercase "L" is for length.
"w" is for width.
The lighter square is 10 units long by 5 inches wide.
A = lw
A = (10 in)(5 in) Multiply
A = 50 in²
Calculate the area for the shaded rectangle, 7 inches by 3 inches.
A = lw
A = (7 in)(3 in) Multiply
A = 21 in²
Calculate the area for the non-shaded region by subtracting the shaded area from the total area.
50 in² - 21 in² = 29 in²
The chance that a point in the large rectangle will NOT be in the shaded region is 29/50.
Convert this fraction to decimal form by using a calculator. Divide the top number by the bottom number.
29/50 = 0.58
0.58 is in decimal form. To convert it to a percentage, multiply the number by 100.
0.58 = 58%
Therefore the probability that a point chosen inside the large rectangle is not in the shaded region is 58%.
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 .