1. How do we multiply and divide these things?
I hate to ask it…
How do we multiply and divide these things?

2. Before we begin Remember multiplying binomials?
(Binomials are things with two terms)
Ex. (x – 2), (y + 7), (3 + 5z)
To multiply two binomials, we had to multiply each part of each binomial
FOIL
First, Outer, Inner, Last

3. Multiplying binomials
(x+3)(x-5)
Multiply first terms: x*x=x2
Multiply outer terms: x*(-5)=-5x
Multiply inner terms: 3*x=3x
Multiply last terms: 3*(-5)=-15
Add them all together: x2-5x+3x-15
Combine like terms: x2-2x-15

4. Important cases Squaring binomial (x+y)(x+y)=(x+y)2 =x2+2xy+y2
Conjugates
(x+y)(x–y)=x2-xy+xy-y2
x2-y2

5. Treat complex numbers like binomials, ¡que facil!
(3-6i)*2i
=3*2i–6i*2i
=6i-12i2
=12+6i
You need to remember to simplify the i and combine like terms!

6. Examples