Answer:
The factors are
.
The factors are not 
Step-by-step explanation:
Equation is
.
This equation can be written as follows:

Here,

Therefore,

So, the factors are
.
The factors are not 
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.
3 4/5 because if 5 only goes into 19 3 times and then there is 4/5 left
Answer:
63/500
Step-by-step explanation: