Answer:
approx 15.5 hours
Step-by-step explanation:
475/30 = 15.83 miles per hour
245 = 15.83·t
t = 245/15.83
t = 15.5 hours
<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:
Step-by-step explanation:
(f*g)(x) = (-5x² + 2x + 7) (x +1)
= x* (-5x² + 2x + 7) + 1*(-5x² + 2x + 7)
= x*(-5x²) + x*2x + x*7 - 5x² + 2x + 7
= -5x³ + 2x² + 7x - 5x² + 2x + 7
= - 5x³ + <u>2x² -5x²</u> <u>+ 7x + 2x </u>+7 {Combine like terms}
= -5x³ - 3x² + 9x + 7
4) (f*g)(x) = (x² + 2x + 4)(x - 2)
= x*(x² + 2x + 4) - 2*(x² + 2x + 4)
= x*x² + x*2x + x*4 - 2*x² - 2*2x -2* 4
= x³ + 2x² + 4x -2x² -4x - 8
= x³ - 8
