Complex Numbers

Complex Numbers

Learning Target: I can simplify expressions with complex numbers.

Adding Complex Numbers

• When adding complex numbers

  -Add real parts together

  -Add imaginary parts together

Multiple Choice

Find the Sum

3i + 2i

• 5i

• 5i²

• 6i

• -5

Multiple Choice

Find the sum.

(5-2i) + (-7+8i)

• -2+6i

• 12+6i

• -35-16i²

• -35 -16i

Subtracting Complex Numbers

• Distribute the negative

• Add real parts together

  Add imaginary parts together

Fill in the Blanks

 $-3+6i-\left(-5-3i\right)-8i$  

Multiple Choice

Simplify:

(10+ 15i) - (48 - 30i)

• 58 - 45i

• 58 - 15i

• -38 - 15i

• -38 + 45i

Multiplying Complex Numbers

• Use an area model.

• Multiply to get insides

• Add like terms

• simplify i²

• Write as a sum

Multiple Choice

(2i)(3i)

• 5i

• -5

• 6i

• -6

Fill in the Blanks

 $4i\left(-2-8i\right)$  

Multiple Choice

(3+8i)(-2-i)

• 2-19i

• 23-i

• 34+5i

• 23-i

Fill in the Blanks

 $\left(1-7i\right)^2$