Answer:
(a) \frac{-1i}{2}-1[/tex]
(b) 
(c) i
Step-by-step explanation:
We have to perform division
(a) 
So after division
(b) We have given expression 
After rationalizing 
(c) We have given expression 
After rationalizing
If you expand out the brackets you get this,
(4+5i)(a+2i) = 4a + (5a)i + 8i - 10
The -10 comes from 5i * 2i.
Squaring i becomes -1.
Let's group the real stuff together,
and imaginary separately,
(4a - 10) + (5a + 8)i
For this to be purely imaginary,
the real part needs to be zero.
Therefore 4a - 10 = 0
Solve for a.
The shortest distance between 2 concentric circles is the difference of their radii. Thus the answer is 8-2=6
Answer:
Andre's Method is the only one that works
Step-by-step explanation:
Noah's method won't work because he doesn't follow the order of operations. You can pull the the 9 out first you have to distribute the 2 first.
Elena's method doesn't work because to eliminate the 18 you must use the reverse operation it must be added not subtracted.
Andre's Method is the only one that works
Answer:
55
Step-by-step explanation:
There are 11 tens in 110, so 11 times 5 is 55.
