Imaginary Complex

What is the conjugate of the following...
7-2i

• 7 - 2i

• -7 - 2i

• -7 + 2i

• 7 + 2i

What is the conjugate of the following... 4+i

• 4 + i

• -4 + i

• -4 - i

• 4 - i

Rationalize the denominator and simplify completely.

(5i)³

• 125

• -125i

• -15

• 15i

• 2i

• -2i

• 2

• 4i

• -√23

• 23i

• 23

• i√23

• 5

• -5

• 5i

• -5i

Simplify √-45

• 3i√5

• -3i√5

• -i√45

• 45i

What letter usually represent imaginary number?

• a

• i

• j

• x

• A
• B
• C
• D