SOLUTION: {{{(x-2)(x+4)+p=0}}}. Roots = m,n. m=n, find p

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: {{{(x-2)(x+4)+p=0}}}. Roots = m,n. m=n, find p      Log On


   

Question 705658: %28x-2%29%28x%2B4%29%2Bp=0. Roots = m,n. m=n, find p
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
General form x^2+2x+(p-8)=0

x=%28-2-sqrt%284-4%28p-8%29%29%29%2F2 OR x=%28-2%2Bsqrt%284-4%28p-8%29%29%29%2F2

Simplifies to
x=-1-sqrt%28-7-p%29 OR x=-1%2Bsqrt%28-7-p%29

continuing, ... -sqrt%28-7-p%29=sqrt%28-7-p%29, because both roots are specified as equal
0=2%2Asqrt%28-7-p%29
0=4%2A%28-7-p%29
-28=4p
highlight%28p=-7%29

x will then be found to be -1, highlight%28x=-1%29