9514 1404 393
Answer:
- 320 m after 8 seconds
- 5.6 seconds, 10.4 seconds to height of 290 m
Step-by-step explanation:
To find the height at 8 seconds, evaluate the formula for t=8.
S(t) = -5t^2 +80t
S(8) = -5(8^2) +80(8) = -320 +640 = 320
The height of the rocket is 320 meters 8 seconds after takeoff.
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To find the time to 290 meters height, solve ...
S(t) = 290
290 = -5t^2 +80t
-58 = t^2 -16t . . . . . . . divide by -5
6 = t^2 -16t +64 . . . . . complete the square by adding 64
±√6 = t -8 . . . . . . . . . take the square root
t = 8 ±√6 ≈ {5.551, 10.449}
The rocket is at 290 meters height after 5.6 seconds and again after 10.4 seconds.
Answer:
m=3
Step-by-step explanation:
18=5m+3
15=5m
m=3
Answer:
y=8
Step-by-step explanation:
4−2y+3=−9
Step 1: Simplify both sides of the equation.
4−2y+3=−9
4+−2y+3=−9
(−2y)+(4+3)=−9(Combine Like Terms)
−2y+7=−9
−2y+7=−9
Step 2: Subtract 7 from both sides.
−2y+7−7=−9−7
−2y=−16
Step 3: Divide both sides by -2.
−2y
−2
=
−16
−2
y=8
Answer:
(4x^3)^3
Step-by-step explanation:
64x^9
divide each exponent by 3 to get a cube
((64^-3)x^3)^3
simplify
(4x^3)^3
Answer:
81m^6 - 323 m^5 + 432m^4 - 192m^3
Step-by-step explanation:
Comment
If you are given choices, you should list them please. Otherwise we cannot be certain our answers are taken far enough.
The general formula for expanding a binomial raised to the third power is
(a - b)^3 = a^3 - 3a^2b + 3ab^2 - b^3
Solution
To modify the general formula to suit this problem, let
a = 3m
b = - 4
When that is done, the general equation becomes
(3m)^3 - 3* (3m)^2 * 4 + 3 * 3m * 4^2 - 4^3
(3m - 4)^3 = 27m^3 - 108 m^2 + 144m - 64
Multiply everything in the 4-nomial by 3m^3
(27m^3 - 108 m^2 + 144m - 64)3m^3
81m^6 - 323 m^5 + 432m^4 - 192m^3 which is your answer. I see why you didn't include it, with other (incorrect) possibilities.
