3x^2-5=0 completing square

3x = 729 solve for x plz . it's urgent. will mark

Aresearcher believes increased perceived control influence the well-being of residents at a nursing home. to test this , she allowed one group of residents to have control over their daily lies, (where to eat etc) . the other group of 5 residents had these deceisions made by staff. the resident's feelings of well-being were measured on a 10 point scale at the end of a one month trial period. is there a difference on well-being?

24m^2n+30mn^2+18mn, a sweet challenge!