What the student did it's right but there's one more step missing.
The slope-intercept form is:
[tex]y=mx+b[/tex]
a. The student didn't clear y
b. We have to divide both sides by 2:
[tex]\begin{gathered} 2y=-4x+6 \\ \frac{2y}{2}=-\frac{4x}{2}+\frac{6}{2} \\ y=-2x+3 \end{gathered}[/tex]
c. The correct answer is y = -2x+3
