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I need help please

n^2=18n+40

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Elisha A. | A passion for teaching economics and mathematicsA passion for teaching economics and mat...
5.0 5.0 (1 lesson ratings) (1)
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n^2=18n + 40
n^2 - 18n - 40=0
n^2 -20n + 2n - 40=0
n(n - 20) + 2(n - 20)=0
therefore;
(n + 2) (n- 20)=0
Hence n = -2,20
Parviz F. | Mathematics professor at Community CollegesMathematics professor at Community Colle...
4.8 4.8 (4 lesson ratings) (4)
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n ^2 = 18n + 40
 
n ^2 - 18n - 40 = 0
 
n^2 + 2n - 20n - 40 =0 
 
n ( n +2 ) - 20 ( n + 2 ) = 0
 
( n + 2 ) ( n - 20 ) = 0
 
 n + 2 = 0 , n = - 2    n -20 = 0 ,n = 20