SOLUTION: please help me if any one can if x^2-63x-64=0 and p and n are integers such that p^n=x,which of the following cannot be a value for p? (A)-8 (B)-4 (C)-1 (D)4 (E)64 PLEA

Algebra ->  Equations -> SOLUTION: please help me if any one can if x^2-63x-64=0 and p and n are integers such that p^n=x,which of the following cannot be a value for p? (A)-8 (B)-4 (C)-1 (D)4 (E)64 PLEA      Log On


   

Question 926307: please help me if any one can
if x^2-63x-64=0 and p and n are integers such that p^n=x,which of the following cannot be a value for p?
(A)-8
(B)-4
(C)-1
(D)4
(E)64
PLEASE ANSWER ME ACCORDING TO THE CAPS
Found 2 solutions by MathLover1, MathTherapy:
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

if x%5E2-63x-64=0 and p and n are integers such that p%5En=x, then

%28p%5En%29%5E2-63p%5En-64=0
p%5E2n-63p%5En-64=0.......use quadratic formula
p%5En+=+%28-%28-63%29+%2B-+sqrt%28+%28-63%29%5E2-4%2A1%2A%28-64%29+%29%29%2F%282%2A1%29+
p%5En+=+%2863+%2B-+sqrt%283969%2B256+%29%29%2F2+
p%5En+=+%2863+%2B-+sqrt%284225+%29%29%2F2+
p%5En+=+%2863+%2B-+65%29%2F2+
solutions:
p%5En+=+%2863+%2B+65%29%2F2+
p%5En+=+128%2F2+
p%5En+=+64+
or
p%5En+=+%2863-65%29%2F2+
p%5En+=-1%2F2+



solutions for variable p
p+=+%28-1%29%5E%281%2Fn%29
p+=+64%5E%281%2Fn%29
so, when p+=+-1 we have an integer solution
%2864%5E-1%29%5E2-63%2A64%5E-1-64=0
%281%2F64%29%5E2-63%2A%281%2F64%29-64=0
1%2F4096-63%2F64-64=0
0.000244140625-0.984375-64=0
-0.984130859375-64=0

-64.984130859375%3C%3E0; so, highlight%28p+=+-1%29 cannot be a value for p
because gives us -64.984130859375%3C%3E0

p can be 64 because ++n+=+1 and
%2864%5E1%29%5E2-63%2A64%5E1-64=0
%2864%5E1%29%5E2-63%2A64%5E1-64=0
4096-4032-64=0
4096-4096=0
0=0

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

please help me if any one can
if x^2-63x-64=0 and p and n are integers such that p^n=x,which of the following cannot be a value for p?
(A)-8
(B)-4
(C)-1
(D)4
(E)64
PLEASE ANSWER ME ACCORDING TO THE CAPS
x%5E2+-+63x+-+64+=+0

(x - 64)(x + 1) = 0

x = 64, or x = - 1

A.
p = - 8
p%5En+=+x
%28-+8%29%5E2+=+64
Thus, - 8 CAN BE a value for p

C.
p = - 1
p%5En+=+x
%28-+1%29%5E3+=+-+1
Thus, - 1 CAN BE a value for p

D.
p = 4
p%5En+=+x
%284%29%5E3+=+64
Thus, 4 CAN BE a value for p

E.
p = 64
p%5En+=+x
%2864%29%5E1+=+64
Thus, 64 CAN BE a value for p

highlight_green%28-+4%29, or CHOICE B CANNOT be a value for p