A rational number is any number that is a fraction percent, decimal, or a whole,natural number
The right answer is -13/12.
Decay word problem:
Uranium-238 decays by 25% every 30 minutes, if you have 200g of Uranium-238, how much Uranium do you have after 4 hours?
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Answer:
-4y = x², or y = - x²/4, or y = -(1/4)x²
Step-by-step explanation:
Because the focus is beneath the directrix, this vertical parabola opens down. The general formula is 4py = x².
Because the distance between focus and directrix is 2 units, p = -1 here. The negative sign shows that the parabola opens down.
4py = x² becomes 4(-1)y = x², or -4y = x², or y = - x²/4
3x² - 78 = 114
3x² = +78 + 114
3x² = 192
x² = 192/3
x² = 64 and x = -+ √64, x' =8 and x" =-8