Question

2x+1/x=5 then what is the value of 4x²+1/x²=??​

Answer 1

$2x + \frac{1}{x} = 5$

SQUARING ON BOTH SIDES

${(2x + \frac{1}{x}) }^{2} = {5}^{2}$

${4x}^{2} + \frac{1}{ {x}^{2} } + 2(2x)( \frac{1}{x}) = 25$

${4x}^{2} + \frac{1}{ {x}^{2} } + 4 = 25$

${4x}^{2} + \frac{1}{ {x}^{2} } = 21$

Answer 2

Step-by-step explanation:

2x+1/x=5

2x+1=5x

3x=1

x=1/3

now put the value of x in required problem

4×1/9 +1 /1/9

you will get the rquired answer

=13