Find an equation of the line in the form ax + by=C, where a, b, and c are integers with no factor common to all three and a ≥ 0. The line with y-intercept 4 and perpendicular to x + 3y = 13 The equation of the line in the form ax+by=c, with y-intercept 4 and perpendicular to x+3y=13 is ____ (Simplify your answer.)