Complex numbers

Simplify: 
(10+ 15i)-(48 - 30i)

• 58 - 45i
• 58 - 15i
• -38 - 15i
• -38 + 45i

Simplify: 
(7 + 2i)(9 - 6i)

• 75-24i
• 63 - 24i  - 12i²
• 51 - 24i
• 58 + 60i

What does i² = ?

• -1
• √-1
• 1
• -√1

Simplify
3i - (4 + 7i)

• -4 + 10i
• 21 - 12i
• 4 - 10i
• -4 - 4i

Find the sum.
(5-2i) + (-7+8i)

• -2+6i
• 12+6i
• -35-16i²
• -35 -16i

Multiply
(2i)(3i)

• 5i
• -5
• 6i
• -6

The expression (2 + 3i)² is equal to

• -5
• -5 + 12i
• 13
• 13 + 12i

(-5 + 10i)(-5 - 10i) = 125

• True

• False

What letter represents an imaginary number?

• a

• i

• j

• x

• 10
• -10
• 10i
• -10i