I'm assuming your teacher wants you to calculate the speed
1/2 = 0.5
3 & 1/2 = 3 + 1/2 = 3 + 0.5 = 3.5
If a plane flies 840 miles in 3.5 hours, then,
speed = distance/time
speed = (840 mi)/(3.5 hr)
speed = (840/3.5) mph
speed = 240 mph
<h3>Answer: 240 mph</h3>
Answer:

Step-by-step explanation:
40ab is 40 multiplied by a multiplied by b
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)