Answer:
a) x = -10
b) x = 7
Step-by-step explanation:
a)
2(x + 3) = x - 4
2x + 6 = x - 4
2x - x = -4 - 6
x = -10
b)
4(5x - 2) = 2(9x + 3)
20x - 8 = 18x + 6
20x - 18x = 6 + 8
2x = 14
x = 7
Answer:
The sample size required is at least 171
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
So it is z with a pvalue of 
, so 
Now, find the margin of error M as such
In which 
is the standard deviation of the population and n is the size of the sample.
What sample size is required?
A samle size of at least n is required, in which n is found when 
So
Rouding up
The sample size required is at least 171
If you search the internet you can find the answer I hope you can find the answer
Answer:
4 mi/h
Step-by-step explanation:
The distance between the cyclists is the hypotenuse of an isosceles right triangle. The hypotenuse is √2 times the length of the legs in such a triangle, so each cyclist must have ridden 8 miles in 2 hours.
Their speed is (8 mi)/(2 h) = 4 mi/h.
_____
<em>Additional comment</em>
Consider an isosceles right triangle with leg lengths 1. Then the Pythagorean theorem tells us the length of the hypotenuse is ...
c² = a² +b² . . . square of hypotenuse is sum of squares of legs
c² = 1² +1² . . . . both legs are 1 in our example triangle
c² = 2
c = √2
That is, the hypotenuse is √2 times the leg length.
216x-6x=1
210x=1
x= 1/210
x= 0.00476
