
Garnet H. answered 03/23/13
Calculus, Physics, Stat, Linear Algebra, GRE, GMAT, SAT... Tutoring
separate the first two terms on the left and factor out 5
5(m² + (12/5)m ) + 6 = 0
take half the middle coefficient (12/5), square it, and add it to the terms in parentheses
5(m² + (12/5)m + 36/25) + 6 = 0 + 36/5 (this has the effect of adding 36/5 to both sides)
simplify and rearrange:
5(m + 6/5)² = 6/5 ===> (m+6/5)² = 6/25
square root both sides:
m+6/5 = ±√6/5
m = (-6+√6)/5 or m = (-6-√6)/5