quadratic

if A and B are the roots of x2-8x+4M=0 and C and D x2-72X+4N=0 if A<B<C<d and A,B,C,D are in GP then MN=

A)729/4

B)27/16

C)729

D)243

3 Answers

62
Lokesh Verma ·

AB=4M
A+B=8

C+D=72 = r2(A+B)
CD=4N = r4AB

thus, 72=r2.8
r=3

A+Ar=8

thus, A=2

B=6, C=18, D=54

ABCD= ?

62
Lokesh Verma ·

MN=1.3.9.27=27.27=729

1
Optimus Prime ·

yes it is correct

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