The point-slope form equation is y - y1 = m(x - x1). Because we are trying to find the equation that passes through (2,3), use these values as x1 and y1. In this equation m is the slope and we are also given that the slope is -1. This means that the equation in point-slope form is y-3 = -1(x - 2). By simply moving some terms, this can be put in standard form. Multiply out the -1 and then add the 3 to both sides. This gives you y = -x + 5. Because we are trying to find y and we already know that x = 5, so put this into the equation. y = -(5) + 5 = 0. For future reference, to check the points that an equation passes through, you can graph the equation and see if the points asked for align with the graph equation you made (I already did this and it is correct). Hope this helps! :)
