D is the correct answer
x+5=10: subtract 5 from both sides the 5 will cancel out leaving x=5
x+5=10
-5 -5
x=5
<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:
B.
Step-by-step explanation:
= x(8 -8) +(10 +13)
= 0 +23
= 23
Selection D is appropriate.
Answer:
1st question is 1:2
2nd question is 5
Step-by-step explanation:
15 times two is 30, so if you divide both 15 and 30 by 15, you get 1:2
Divide 300 and 60 and you get 5.
