SOLUTION: In solving the equation (x+4)(x-7)=-18, Eric stated that the solution would be x+4=-18=>x=-22 or (x-7)=-18=>x=-11 However, at least one of these solutions fails to work when subst

Question 471462: In solving the equation (x+4)(x-7)=-18, Eric stated that the solution would be x+4=-18=>x=-22 or (x-7)=-18=>x=-11 However, at least one of these solutions fails to work when substituted back into the original equation. Why is that? Please help Eric to understand better; solve the problem yourself, and explain your reasoning.
Answer by mananth(16946) (Show Source): You can put this solution on YOUR website!
(x+4)(x-7)=-18

x=-2 OR x=5
CHECK
(x+4)(x-7)=-18
plug x=-2
(-2+4)(-2-7)=-18
plug x=5
((5+4)(5-7))=-18
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