Answer:
Last equation given in the list of possible answers:
5 ( 1.5 + 1.5 + x ) = 25
Step-by-step explanation:
We need to include in the total addition of miles ridden during the week:
a) 1.5 miles to the school
b) 1.5 miles from school back home
c) x miles for the evening ride
so for the miles ridden per day we have: "1.5 +1.5 + x"
Now, since per week she does 5 days like this, then we need to multiply the expression above by 5 in order to total the number of miles she rides weekly (25 miles)
5 ( 1.5 + 1.5 + x ) = 25
And we can use this equation to find the amount "x" that Rin rides in the evening.
Try writing it in point-slope form and you will see why you have a problem.
slope m is equal to (y2-y1)/(x2-x1):
m = (y2-y1)/(x2-x1) = (2-6)/(-6 - -6) = -4/0
The denominator has a zero, so it is undefined.
Since the point-slope form requires "m" to be defined, you can't write the equation of the line using point-slope form.
Notice this is a geometric progression since each number multiplied by some factor equals the next number in the sequence, in this case,
Then by applying the formula for sum to infinity of a geometric progression,
<h3>
Answer: 375</h3>
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Work Shown:
a = 300 = first term
r = 60/300 = 0.2 = common ratio
We multiply each term by 0.2, aka 1/5, to get the next term.
Since -1 < r < 1 is true, we can use the infinite geometric sum formula below
S = a/(1-r)
S = 300/(1-0.2)
S = 300/0.8
S = 375
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As a sort of "check", we can add up partial sums like so
- 300+60 = 360
- 300+60+12 = 360+12 = 372
- 300+60+12+2.4 = 372+2.4 = 374.4
- 300+60+12+2.4+0.48 = 374.4+0.48 = 374.88
and so on. The idea is that each time we add on a new term, we should be getting closer and closer to 375. I put "check" in quotation marks because it's probably not the rigorous of checks possible. But it may give a good idea of what's going on.
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Side note: If the common ratio r was either r < -1 or r > 1, then the terms we add on would get larger and larger. This would mean we don't approach a single finite value with the infinite sum.
Answer:
none of them
Step-by-step explanation:
