Question

Point-slope form to slope-intercept form

Answer 1

y=mx+b
y-y1=m(x-x1)

They are different, and the conversion depends on what you need.

What you need:
y-y1=m(x-x1)
y-y1=mx-mx1 (distribute the m)
y=mx-mx1+y1 (move the y1)
y=mx+b (combine mx1 and y1)