Whats this question im confused 9/250

Awasher and a dryer cost $701 combined. the washer costs $51 more than the dryer. what is the cost of the dryer?

Suppose you are choosing a 6-digit personal access code. this code is made up of 4 digits chosen from 1 to 9, followed by 2 letters chosen from a to z. any of these digits or letters can be repeated. find the total number of personal access codes that can be formed. 492,804 341,172 39,917,124 4,435,236

Let x = a + bi and y = c + di and z = f + gi. which statements are true?