Philip P. answered 07/30/14
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Let m and n be the two numbers. We have two unknowns (m and n) so we need two equations to solve for m and n:
m*n = 891 [Product of the two numbers is 891]
m-n = 6 [Difference of the two numbers is 6]
From the second equation, m = 6+n. Now let's substitute 6+n in place of m in the first equation:
m*n = 891
(6+n)*n = 891 [Substituted 6+n in place of m]
6n + n2 = 891
n2 + 6n - 891 = 0
Factors to:
(n+33)(n-27) = 0
n = -33, 27
Solve for m:
m = 6 + n
m= 6 + (-33) = -27
m= 6 + (27) = 33
There are two solution sets, (m,n) = (-27, -33) and (33,27)
CHECK:
m*n=891
(-27)*(-33) = 891
891 = 891
(33)*(27) = 891
891 = 891
m-n = 6
(-27)-(-33) = 6
-27 + 33 = 6
6 = 6
33 - 27 = 6
6=6