For all sets A, B, and C, (A - B )- C = A - (B-C)

if and only if

A ∩ B= Ø
A ∩ C= Ø
B ∩ C= Ø
A ∩ B ∩ C=Ø. ( I think is this one)

Complete the statements about the system of linear equation respresented by the tables the equation respented the left table is

The average hourly earnings for a construction worker is projected to be $24.50 in 2012. jason wants to join the construction work force after he graduates in 2012. his friend tells him that average hourly earnings for construction workers will rise by 2% from 2009 to 2012. based on the data below, assuming that the projected hourly earnings are correct, is jason’s friend’s statement accurate? construction industry - average hourly earnings, 2000-2009 a. his friend’s statement is accurate. the average hourly earnings will increase by 2%. b. his friend’s statement is not accurate. the percent increase will be more than 2% c. his friend’s statement is not accurate. the percent increase will be less than 2% d. his friend’s statement is not accurate. the average hourly earnings will decrease

How can you construct perpendicular lines and prove theorems about perpendicular lines