Instead of finding a line for an equation, as we discussed in our previous article, we will now learn how to find an equation for a line. All we need to determine an equation for a line is to know a lien's slope and only one point through which the line passes. With this information, we are prepared to find a line for an equation. Suppose we have a slope m and a point (a, b). y - b/x - a = m. Let's pretend we're trying to find an equation for a line through the point (4, -8) with slope 5. We would write y - (-8)/x - 4 = 5. We would then write y + 8 = 5(x-4). This gives us y = 5x - 28.