complex number

Question

If (2x2-3x+1)(2x2+5x+1) =9x2, then eqn has a) Four real roots b) Two real and two imaginary c) Four imaginary roots d) none

jitender lakhanpal · Accepted Answer

Dear pooja,

correct option is a)

solution

(2x²-3x+1)(2x²+5x+1) =9x²

divide the equation by x^2 where x not equal to 0

(2x-3+1/x)(2x+5+1/x) = 9

let 2x+1/x = y put in the equation

(y-3)(y+5) = 9

y²+2 y - 24 = 0

solving the equation we get y = -6 and y = 4

so we get

2x+1/x = -6 and

2x+1/x = 4 we get

2x²+6x+1=0 finding discriminant we get it as +ve so 2 real roots

2x²-4x+1=0 and again finding discriminant we get it as +ve so 2 real roots so the total of 4 real roots

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Algebra> complex number...

If (2x²-3x+1)(2x²+5x+1) =9x², then eqn has

a) Four real roots

b) Two real and two imaginary

c) Four imaginary roots

d) none

pooja sarkar , 14 Years ago

jitender lakhanpal

LIVE ONLINE CLASSES

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Algebra> complex number...

If (2x2-3x+1)(2x2+5x+1) =9x2, then eqn has a) Four real roots b) Two real and two imaginary c) Four imaginary roots d) none

pooja sarkar , 14 Years ago

jitender lakhanpal

LIVE ONLINE CLASSES

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If (2x²-3x+1)(2x²+5x+1) =9x², then eqn has

a) Four real roots

b) Two real and two imaginary

c) Four imaginary roots

d) none