Answer: A, B, C, and E
Step-by-step explanation:
If both sides are real numbers, then the product will be a real number.
If in at least one of the sides we have a complex number, then the product will be real if:
The other number is zero.
The other number is the conjugate of the first.
This is when:
Suppose we have a number:
z = a + b*i
The conjugate will be:
w = a - b*i
And the product between them is:
(a + b*i)*(a - b*i) = a^2 + a*b*i - a*b*i + b^2 = a^2 + b^2
Then the options that will have a real answer are:
A. (4+5i)(4-5i) = 4^2 + 5^2 = 16 + 25 = 41
B. (4 + 91)*(41 - 9) = 3040
C. (3 + 2*i)*(3 -2*i) = 3^2 + 2^2 = 9 + 4 = 13
E. (312 + 7i)*(312 - 7i) = 312^2 + 7^2 = 97,393
Answer: she must sell 6 large photos and 6 small photos
Step-by-step explanation: and how I knew that is I multiplied 6 40 times and that gives you 240 and if you multiply 6 ten times that gives you 60 so 240 plus 60 is $300
Answer:
We don´t have at 95% of confidence, evidence to reject the publisher´s claim
Step-by-step explanation:
Population mean p₀ = 58 % or p₀ = 0,58
Hypothesis Test:
Null Hypothesis H₀ p = p₀
Alternative Hypothesis Hₐ p < p₀
For a significance level α = 0,05 means that CI = 95 % or CI = 0,95
z(c) = - 1,64
MOE = z(c)* √(p*q)/n
p - p₀ / √(p*q)/n = z(s)
And that z(s) is in the acceptance region
|z(s)| < |z(c)|
|z(s)| < 1,64
Then if that so we fail to reject H₀ . We don´t have evidence to reject the publisher´s claim
1/10 of 3,000 is 300.
This is because 300 x 10 = 3,000