Correctly rewriting the equations in the form \(y = mx + c\)
\(y = 4x + 3\) AND \(y = 4x - 6{\cdot}5\)
(so lines parallel) | B3 | B2 for:- one correct equation and a correct but incomplete rearrangement of the other seen
e.g. \(y = 4x - 6{\cdot}5\) and \(3y = 12x + 9\) - both in the form \(y = 4x + c\) with an error in one constant term, provided constants aren’t equal.
e.g \(y = 4x - 6{\cdot}5\) and \(y = 4x + 9\)
B1 for:- one correct equation
\(y = 4x - 6{\cdot}5\) or \(y = 4x + 3\) - two equations of the form \(y = 4x + \ldots\) with errors in both constant terms or no constant terms.
Allow all marks for equivalent complete methods e.g. \(6y - 24x = 18\) AND \(6y - 24x = -39\) or (\(3y = 12x + 9\) AND \(3y = 12x - 19{\cdot}5\)) and a clear statement that the two equations are of the same form and the only difference is the constant, so they are parallel. |
