Answer:
7 -5i
Step-by-step explanation:
The additive inverse is the number we add to make it equal to zero
-7+5i + x = 0
the real part
-7 + x = 0
x = 7
The imaginary part
5i+x = 0
x = -5i
The complex x is
7 -5i
Notice it is the opposite of the number
- (-7+5i)
7-5i
Answer: c)
Step-by-step explanation:
This can be done through trial-and-error. Use the pythagoreas' theorem 
and if the left side of the equation is equal to the right, that is the answer.
(Do take note that c is the longest side.)
a)
Since 
, a) is wrong.
b)
Since 
, b) is wrong.
c) (answer)
Since 
, c) is correct.
d)
Since 
, d) is wrong.
Answer:
10 miles per 1/4 hour
40 miles per hour
Step-by-step explanation:
Given that:
A car travels 20 miles in 1/2 hour
Miles traveled per hour :
(20 * 2) / 1 = 40 miles per hour
Mile traveled in 1/4 hour :
Distance = speed * time
Distance = 40 mph * 1/4 = 10 miles per 1/4 hour
Car traveling 30 miles in 3/4 hours
(30 * 4) /3 = 120 / 3 = 40 miles per hour
Distance = 40 mph * 1/4 = 10 miles per 1/4 hour
Let the number be n.
Then:
n^2 + (1/n)^2 = 82/9; find n. Find the LCD; it is 9n^2.
Mult all 3 terms by 9n^2:
82*9n^2
9n^4 + 9 = (82/9)(9n^2) => 9n^4 + 9 = ------------
9
Then 9n^4 - 82n^2 + 9 = 0
I used my graphing calculator to find that n = 3.
Let's check: is 3^2 + (1/3)^2 = 82/9?
Is 9 + 1/9 = 82/9?
Is 81 + 1 = 82? YES. So, n=3 is a solution.
