Answer: C.)The survey should include all music choices.
Step-by-step explanation: To be honest i'm not sure-.
i have no ideaaaaa HAHAHAHA
I don't really understand this question do u have a pic
Answer: tens
Step-by-step explanation: after ones comes tens, before ones comes decimal point
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.