# MATH TIME!

Discussion in 'User Topics' started by Mr.Lame, Jan 9, 2018.

1. If you're suppose to evaluate the given quadratic expression at t = 2, then 228 is correct:

16t^2 + 80t + 4 = 4(4t^2 + 20t + 1) = 4(4(2)^2 + 20(2) + 1) = 4(16 + 40 + 1) = 4(57) = 4(50 + 7) = 200 + 28 = 228

You would only need to use the quadratic formula (or you could complete the square), if you were asked to solve the equation:

16t^2 + 80t + 4 = 0

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2. ### Mr.LameVeteran

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The answer says it should be 100. I'll type it out once I drop my little one off at school.

Thanks Mark  • Like x 1
3. In order for the expression to equal 100, we can find the correct t by setting:

16t^2 + 80t + 4 = 100

Subtract 100 from both sides:

16t^2 + 80t - 96 = 0

Divide through by 16:

t^2 + 5t - 6 = 0

Factor:

(t + 6)(t - 1) = 0

Using the zero-factor property, we find the solution are:

t = -6, 1

So, the values of t which make the given expression equal to 100 are t = -6 and t = 1. • Like x 1
4. ### Mr.LameVeteran

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Oh gawd, I made a terrible mistake LOL it's -16t^2

I got the right answer now. Sorry mark T.T

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5. You know, I should have realized that, because then it's a kinematic equation, representing the height of a projectile in feet whose initial upward velocity is 80 ft/s and whose initial height is 4 ft. • Like x 1
6. ### Mr.LameVeteran

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Yeah the answer is in ft too hahaha.I need to pay more attention to detail.

Are you going to be on most of the day? I got a quiz tomorrow so, I may lean on you .

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7. I'll be on for the next 4.5 hours or so, then off for 4, then I'll be back for the night. So, go ahead and post 'em up if you got 'em... • Like x 1
8. ### Mr.LameVeteran

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Write the exponential expression in simplest form:
(x^-2y)^2(xy)^-2

so

(x^4y^2)(x^-2y^-2)

Then after that I'm clueless at how to get the answer, 1/x^6

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9. ### Mr.LameVeteran

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OH Woah, I can't believe I didn't figure that out. So when they're in brackets like that we have to times the exponents.

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10. ### Mr.LameVeteran

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sweeeeeeet!!! Just helped me do a even harder equation Got the answer right first try !

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11. ### Mr.LameVeteran

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@MarkFL I have 0 idea how to do this

Perform the indicated operation and wire the answer in scientific notation.
(4.0x10^-9)(8.4x10^5) / (3.0x10^6)(1.4x10^18)

So following what we just did, does that mean we times the numerators together, then the denominators, and finish off by dividing the numbers and subtracting the 10 powers?

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write*

13. ### Mr.LameVeteran

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attachment didn't go through O:

14. I had a typo, and needed to re-upload the image...can you see it now?

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15. ### Mr.LameVeteran

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The 8 is correct it's saying the 10 power should be -16.

16. ### Mr.LameVeteran

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Yup!! also I messed up it's ^-6

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