It might be C. I used the process of elimination, so I'm not so certain
Answer:
28 minutes
Step-by-step explanation:
500 ÷ 18 = 27.77777777777778
Round the 27.7 to 28.
Answer:
as written: 7x^2
perhaps intended: 7x^4
Step-by-step explanation:
As written, the Order of Operations specifies that the only denominator factor is 3, so the expression is interpreted as ...

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Sometimes grouping of denominator factors is intended, but parentheses are not written as they should be. If the intention is ...
21x^3/(3x^-1)
then the simplification is ...

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The applicable rules of exponents are ...
(a^b)(a^c) = a^(b+c)
a^b/a^c = a^(b-c)
Answer:
r = 6
Step-by-step explanation:
Using Pythagoras' identity in the right triangle
PR² = PQ² + QR² , substitute values
(r + 4)² = r² + 8²
r² + 8r + 16 = r² + 64 ( subtract r² from both sides )
8r + 16 = 64 ( subtract 16 from both sides )
8r = 48 ( divide both sides by 8 )
r = 6