What is the solution set of x2 + y2 = 26 and x − y = 6? A. {(5, -1), (-5, 1)} B. {(1, 5), (5, 1)} C. {(-1, 5), (1, -5)} D. {(5,
Rus_ich [418]
He two equations given are
x^2 + y^2 = 26
And
x - y = 6
x = y +6
Putting the value of x from the second equation to the first equation, we get
x^2 + y^2 = 26
(y + 6) ^2 + y^2 = 26
y^2 + 12y + 36 + y^2 = 26
2y^2 + 12y + 36 - 26 = 0
2y^2 + 12y + 10 = 0
y^2 + 6y + 5 = 0
y^2 + y + 5y + 5 = 0
y(y + 1) + 5 ( y + 1) = 0
(y + 1)(y + 5) = 0
Then
y + 1 = 0
y = -1
so x - y = 6
x + 1 = 6
x = 5
Or
y + 5 = 0
y = - 5
Again x = 1
So the solutions would be (-1, 5), (1 , -5). The correct option is option "C".
Answer:
I THINK A
Step-by-step explanation:
Answer:
its c and its right
Step-by-step explanation:
Answer:
29.5+/-1.11
= ( 28.39, 30.61)
Therefore, the 90% confidence interval (a,b) =( 28.39, 30.61)
Step-by-step explanation:
Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.
The confidence interval of a statistical data can be written as.
x+/-zr/√n
Given that;
Mean x = 29.5
Standard deviation r = 5.2
Number of samples n = 59
Confidence interval = 90%
z-value (at 90% confidence) = 1.645
Substituting the values we have;
29.5+/-1.645(5.2/√59)
29.5+/-1.645(0.676982337100)
29.5+/-1.113635944529
29.5+/-1.11
= ( 28.39, 30.61)
Therefore, the 90% confidence interval (a,b) =( 28.39, 30.61)
I pretty sure it is D if you give me a thanks I would really appreciate it
