How to find the standard form of an ellipse?

Factor. 8x2y2 – 4x2y – 12xy 4(8x2y2 – x – 12xy) 4(2xy – 4x2y – 12xy) 4x2y2(2xy – xy –3) 4xy(2xy – x – 3)

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

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?