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View Full Version : Solve x2 + 18x + 81 = 0


kathy1978
Oct 15, 2010, 09:00 AM
Solve x2 + 18x + 81 = 0

Unknown008
Oct 15, 2010, 09:53 AM
What are the factors of 81 which add up to 18?

lighunt
Oct 27, 2010, 10:06 AM
You basically need X2 and 18X to add up to a negative 81. So subtract 81 from both sides to create the equation of X2 + 18X = -81. Now add X2 + 18X. This will create the equation of 20X = -81. Now divide 20 on both sides... X = -4.05.

Unknown008
Oct 27, 2010, 10:29 AM
You basically need X2 and 18X to add up to a negative 81. So subtract 81 from both sides to create the equation of X2 + 18X = -81. Now add X2 + 18X. This will create the equation of 20X = -81. Now divide 20 on both sides...X = -4.05.

This is not the correct answer. :rolleyes: