Answer:
we can not draw on here
Step-by-step explanation:
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.
inside angles need to equal 180
180-75-40 = 65
now the question mark and 65 need to equal 180
180-65 = 115
answer is 115
Answer:
v=8
Step-by-step explanation:
