Answer:
x = 8 or x = -8
Step-by-step explanation:
x^4 - 256 = 0
<=>x^4 - 4^4 = 0
<=>(x - 8)(x + 8)(x^2 + 64) = 0
Case 1 :
x - 8 = 0
<=>x = 8 (choose)
Case 2:
x + 8 = 0
<=>x = -8 (choose)
Case 3:
x^2 + 64 = 0
<=>x^2 = -64 (nonsense)
so x = 8 or x = -8
Done :))
The amount of variance for y that is predicted by its relationship with x is 64%.
<h3>
How much variance is predicted?</h3>
Variance measures the rate of dispersion of a data point around the dataset. It can be calculated by finding the square of the standard deviation of a dataset. Variance measures the variation of a data set.
Correlation is a statistical measure used to measure the linear relationship that exists between two variables. The greater the correlation coefficient is closer to one, the greater the linear relationship that exists between the two variables. A positive correlation occurs when the two variables move in the same direction.
Variance = (correlation coefficient²) x 100
(0.80²) x 100
0.64 x 100 = 64%
To learn more about correlation, please check: brainly.com/question/27246345
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Answer:
7-4x/y=5
7+5y/x=4
Step-by-step explanation:
hope it's helpful
This means that the bicycle was discounted in total by 60%, so $315 is 40% of the original price to get 40% to 100% youd multiply it by 2.5 so so the same to the price 315 x 2.5= 787.5
Answer:
The length is 12metres, the width is 6metres
Step-by-step explanation:
Suppose the width is x, the length is x+6
The square is 72. The square of rectangular field is equal to product of length and width.
so x(x+6)=72
x^2+6x-72=0
a=1 b=6 c=-72
D= b^2-4ac= 6*6+288= 36+288= 324
sqrtD= 18
x1= (-b-sqrtD)/2a=(-6-18)/2= -12 (it is negative, but width is only positive. So this root doesn't match)
x2=(-b+sqrtD)/2a= (-6+18)/2= 12/2=6 - the width
The length is 6+6=12
