Joseph has started completing the square on the equation where
given equation is
[tex]3x^2-7x+12=0[/tex]
move constant term to other side.
[tex]3x^2-7x=-12[/tex]
divide both sides by coefficient of x^2 that is by 3
[tex]x^2-\frac{7}{3}x=-\frac{12}{3}[/tex]
[tex]x^2-\frac{7}{3}x=-4[/tex]
This is the same step upto which Joseph has worked. But he got different equation
[tex]x^2-x=-4[/tex]
Hence his work is not accurate.