4(x + 9) = x + 9 how does this work can you explain it to me

I'll give brainliest if you answer right : )

Through: (-3,-3) parallel to y= 7/3x+3

Lindsay used two points, (x, y; ) and (+2.82), to find the equation of the line, y = mx + b, that passes through the points. y2-y, first, she used the definition of slope and determined that the value of mis x, - . given this information, which expression must represent the value of b?