(a + b)^3 = a^3 + 3a^2b + 3ab^2+ b^3
(a +(- b))^3 = (a-b)^2 = a^3 - 3a^2b + 3ab^2- b^3
Answer:
27
Step-by-step explanation:
total=average ×no.
18×40=720 the no. of coins for all children
12×24=288 no. of coins for boys
720-288=432 for all girls
one girl, mean,divide 432 by 16= 27
The differences is 7 because I counted.
<h3>
Answer: Choice C) 421.9</h3>
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Explanation:
You're on the right track. You wrote down the proper expression to get the final answer, assuming you meant to write 75/4 as the third term inside the parenthesis. This works because each time you cut the side length in half to get each smaller triangle's side. The 3 is because there are 3 sides for each of the triangles. Much of this I have a feeling you already know as you wrote down the expression on the page, though I'm not 100% sure of your mindset. Computing this expression leads to 421.875 which rounds to 421.9
note: an alternative is to write 3*75 + 3*75/2 + 3*75/4 + 3*75/8, though that is more work. It's better to have that 3 factored out.
