Answer to Question #283643 in Algebra for Ali

Question

If ( x*2 +1/x)*2 =15

Then x=1/x=?

Answer 1

$(2x+\frac{1}{x})*2=15$.

$4x+\frac{2}{x}=15.$

$4x^2-15x+2=0.$

$x_1=\frac{15-\sqrt{193}}{8}\approx 0.1384.$

$x_2=\frac{15+\sqrt{193}}{8}\approx 3.6116.$