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In the question A^B means A raised to the power of B. What is the value of A such that
X^2-11x+A and X^2 -14X +2A will have a common factor?
a) -1/2
b) 24
c) -3
D) 20
Read Solution (Total 6)
-
- X^2-11x+A
let it has p and q as roots
then we can write
p+q = -(-11)/1 = 11 ....(1)
p*q = A.....(2)
X^2 -14X +2A
let it has p and r as the roots
p+s =14......(3)
p*s = 2A......(4)
= 2*p*q, from above equation
=> s = 2q
now (3) => p+2q = 14
(1)=> 2p+2q = 22
solving above two
p = 8
q = 11 - 8 = 3, from equation (1)
A = p*q = 8*3 = 24 , from equation (2)
so A = 24
option b is the answer
- 10 years agoHelpfull: Yes(34) No(0)
- due to quadratic equation..... the factor will be like (x-a)(x-b)
lets assume (x-k) is the common factor the
x=k is the root of both the eqn
X^2-11X+A=0 , & X^2-14X+2A=0
satisfying these two equations we get
k^2-11k+A=0 ..................................(1)
k^2-14k+2A=0 ..................................(2)
on solving we will get
k=A/3
substituting this in eq 1 we get A=0 and A= 24
so A=24 is the answer - 10 years agoHelpfull: Yes(17) No(0)
- Check the options
A.-1/2 we get irrational roots, keep it aside
B.24. X*X-11X+24 =(x-3)(x-8). =3,8
X*X-14X+48 =(x-6)(x-8). =6,8
So b.24 is the answer - 10 years agoHelpfull: Yes(10) No(0)
- X^2-11X+A =0 and X^2-14X+2A=0
by solving both the equs. , we get,
x=A/3 (put in any of the above equ.)
nd get A=24 - 10 years agoHelpfull: Yes(2) No(0)
- b
the common factor is 8 - 10 years agoHelpfull: Yes(0) No(2)
- ans is b
x^2-11x+24 x^2-14x+48
x=12,2 x=6,8 - 9 years agoHelpfull: Yes(0) No(0)
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