5x⁴ - 3x³ + 6x) - (3x³ + 11x² - 8x)<span>
</span>Expand the second bracket by multiplying throughout by -1
5x⁴ - 3x³ + 6x - <span>3x³ - 11x² + 8x
</span>
Group like terms and simplify
5x⁴ - 3x³ - 3x³ - 11x² + 6x <span>+ 8x
</span>5x⁴ - 6x³ - <span>11x² + 14x</span>
Answer: x=2π/3 and x=4π/3
Step-by-step explanation:
The equation we have is 
. All we have to do is get cosine alone to find the 2 values of x.
Now that we have our cosine left, we can use our unit circle to figure out when does cosx=-1/2. Cosine is the x value of the coordinate.
x=2π/3
x=4π/3
Answer:
A) 99.7% of people have an IQ between 64 and 136.
B) 5% of people have an IQ score less than 76 or greater than 124.
C) 16% of people have an IQ score greater than 112.
Step-by-step explanation:
The Empirical Rule tells us that, in a normal or 'bell-shaped' distribution, 68% of the data is one standard deviation from the mean, 95% of the data is two standard deviations from the mean, and 99.7% of the data is three standard deviations from the mean.
A) 64 and 136 are 3 standard deviations away from the mean, so 99.7% of people have an IQ between 64 and 136.
B) 76 and 124 are 2 standard devations away from the mean, but the answer is asking what percentage is not between them. 100% - 95% gives us 5%.
C) 112 is one standard deviation away from the mean. If we want to find the percentage greater, then we can do 100% - 50% (as 112 is to the left of the mean), then we can take half of 68 to get 34%, and after subtracting 50% and 34% from the 100%, we get 16%.
The correct answer is C (-20) let me know if you want to know how I got that answer
X=2
subtract 5x on both sides
-2x=-4
divide by -1 on both sides
2x=4
divide by 2 on both sides
x= 2
