There are two ways to work this out: normal variables or using "imaginary" numbers.
Normal variables:
![(7+2i)(3-i)\\(7*3)+[7*(-i)]+(3*2i)+[2i*(-i)]\\21-7i+6i-2i^{2}\\\\21-i-2i^{2}](https://tex.z-dn.net/?f=%20%287%2B2i%29%283-i%29%5C%5C%287%2A3%29%2B%5B7%2A%28-i%29%5D%2B%283%2A2i%29%2B%5B2i%2A%28-i%29%5D%5C%5C21-7i%2B6i-2i%5E%7B2%7D%5C%5C%5C%5C21-i-2i%5E%7B2%7D)
Imaginary numbers:
Using the result from earlier:

Now since

, then the expression becomes:
Answer:
-1
Step-by-step explanation:
x - 1x - 1
1x = x
x - x -1
x - x = 0
0 - 1 = -1
-1
Answer: x= 21.6
Step-by-step explanation:
12^2 + 18^2 =x^2
144 + 324 =x^2
468 = x^2
c= 21.633
To the nearest tenth place is c= 21.6
Answer:
C
Step-by-step explanation:
Given
m + 5 = 17 ( subtract 5 from both sides )
m = 12 ( multiply both sides by 3 to clear the fraction )
2m = 36 ( divide both sides by 2 )
m = 18 → C