math..solve for u again.
posted by jasmin on .
u2√2=3. please show work

What part of my work don't you understand?
u  √2 = 3
u  1.414 = 3
u = 4.414 
the answer should be 9

sorry. u2√u=3

let x = sqrt u
then
x^2  2 x = 3
x^2  2 x  3 = 
(x3)(x+1) = 0
x = 3 or x = 1
try sqrt u = 3 then u = 9
9  6 = 3 Yes
try sqrt u = 3 , that is an imaginary number, forget it
so
u = 9