Question 1132466
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If  (a-b)^2 - 3(a-b) -18 = 0.  then


    a-b = use the quadratic formula = {{{(3 +- sqrt(3^2 + 4*18))/2}}} = {{{(3 +- 9)/2}}}.


Thus the two roots are


    a-b = {{{(3 + 9)/2}}}  = 6 

and

    a-b = {{{(3 - 9)/2}}} = -3.


Since, according to the condition the value of a-b-6 is not equal to 0, it means that  


    a-b = -3,  and hence  a-b-8 = (a-b+3) - 11 = 0 - 11 = -11.      <U>ANSWER</U>
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