The locus of points equidistant from points A and B is the perpendicular bisector of AB. This itself is a straight line, passing thru the mid-point of AB, viz: M([0+2]/2, [1+3]/2) = (1,2). Gradient of AB is (3-1)/(2-0) = 1; therefore gradient of the perp bisector is -1, with equation: y-2 = -1(x-1), i.e. y = -x + 3.
Now solve for the intersection of the 2 straight lines. y = -x +3 and y = 2x - 9. You should get x=4, y = -1.
Alternatively, you can make P(x,y) that lies on the given line and satisfying the condition: PA = PB.
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Why did you not supply the co-ords of A and B at the outset?