Answer:
b
Step-by-step explanation:
so 17 squared minus 8 squared is 225. the square root of 225 is 15
Divide the total distance traveled by the total time spent traveling. This will give you your average speed. S = 56.67 {\displaystyle S=56.67} . So if Ben traveled 50 mph for 3 hours, 60 mph for 2 hours, and 70 mph for 1 hour, his average speed was about 57 mph.
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
The answer is 2 units up
hope this helps:)
