Answer:
Step-by-step explanation:
subtract 9 from both sides
x=3
Answer:
y = -x + 8
Remember that the slope-intercept form had formula y = mx + b where m is the slope and b is the y-intercept.
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.