Question

solve by completing the square
x^2+(3/2)x=3

Answer 1

really?? ok then, this is not the easiest way to get this answer but
x^2+(3/2)x-3=0
(x+3/4)^2-9/16-3=0
(x+3/4)^2=57/16
\[x+3/4=\pm \sqrt{57/16}\]
\[x=-3/4 \pm \sqrt{57}/4\]

Answer 2

x=1.14 or x=-2.64