Let z = 19 + i and w = 4 + 10i. What is the first step in determining zw?

Replace i2 with –1.
Multiply z by the conjugate of w.
Apply the distributive property or FOIL.
Combine the corresponding real and imaginary parts.

EDGE

You're locked out of your house. the only open window is on the second floor, 25 feet above the ground. there are bushes along the edge of the house, so you will need to place the ladder 10 feet from the house. what length ladder do you need to reach the window?