Patterns
Adding Complex Numbers
Subtracting Complex Numbers
Multiplying Complex Numbers
Dividing Complex Numbers
100

i0=

1

100

1+3i+2i


1+5i

treat the imaginary number as you would a variable.

only add the -3 and 2 


100

-3+12i-2i=

-3+10i

Combine like terms

i goes at end

100

(3i)(8i)=

-24

(3x8)=24 (ixi)=i2=-1

(24)(-1)

100

To find this, you keep the real part  the same and change the sign of the imaginary part bi to −bi

How do you find the conjugate of an expression?

200

i1=

i

200

9+14i+2i=

9+16i


Treat i like a variable 

only add like terms.


200

-8+22i-44i=

-8-22i

Combine like terms

i goes at end

200

(2+4i)(3+5i)=

-14+22i

Foil: 6+10i+12i+20i2

Combine like terms: 6+22i+20i2

Simplify i2: 6+22i-20

Combine again: 

200

1. Identify the conjugate of the denominator

2. Multiply the numerator and the denominator by the conjugate of the denominator

3. Simplify the resulting expression.

What the steps to dividing imaginary numbers?

300

i2=

-1

300

(15+2i)+(16+-1i)=

31+i

(15+2i)+(16+-1i) can be rewritten as 15+16+2i+-1i

combine like terms


300

(15+2i)-(13+i)=

2+i

Change to: 15-13+2i-i

Combine like terms

300

(2-4i)(3-5i)=

-14-22i

Foil:6-10i-12i+20i2

Simplify: 6-22i-20

Combine like terms:


300

(1+2i)/(3+4i)

11/5 - (2/5)i

400

i3=

-i

400

(2-12i)+(-4-12i)=

-2-24i

rewrite as: -12i+-12i+2+-4

combine like terms


400

(15+12i)-(-13+13i)= 

28-i

change to: 15+13+12i-13i

Combine like terms

400

(6+12i)(2-4i)=

60

Foil: 12-24i+24i-48i2

Simplify:12+48

Combine like terms:

400

Find the conjugate of the denominator: 

(12-21i)/(-6-9i)

-6+9i

Switch middle sign.

500

i40=

1

40/4=10 with a remainder of 0

This means i40= i0=1

500

(-322-16i)+(55-12i)=

-267-28i

rewrite as -16i+-12i+-322+55

Combine like terms

500

(144-154i)-(-122+43i)=

266-165i

change to: 144+122+-154i-43i

combine like terms

500

2i(12+4i)(6+8i)=

 -240+80i

multiply 2i: (24i+8i2)(6+8i)

simplify: (8i+24i)(6+8i)

foil: -48-64i+144i+192i2

simplify: -48+80i-192

Combine like terms:

500

Solve: (12-21i)/(-6-9i)

1+2i

Multiply by conjugate over itself:

(12-21i)(-6+9i)/(-6-9i)(-6+9i)

Foil:

(-72+108i+126i+189i2)/(36-54i+54i-81i2)

Simplify:

(-72+234i+189)/(36+81)

Combine like Terms:

(117+234i)/(117)

Divide: