Finite Mathematics and Calculus with Applications (7th Edition) by Lial, Greenwell, and Ritchey Section 1.1- Slopes and Equations of Lines 19. Find the equation of the line through the points and Express the answer in slope-intercept form if possible. The slope of the line is The equation of the line must be To find b we can use the point Substitute and and solve for b. Therefore the equation of the line is 31. Find the equation of the line through perpendicular to Find the slope of the line by solving for this line has slope If 2 lines are perpendicular then their slopes are negative reciprocals. Therefore, a line perpendicular to has slope 1 and must be Using the point we see that Therefore the equation of the perpendicular line through is 35. Do the points , and lie on the same line? If these points lie on the same line, then the slopes of the lines connecting these points must be equal. The slope between and is The slope between and These slopes are not equal, so the points do not line on the same line. 59. Graph the equation To make this graph, get at least 2 points on the graph. Just to make sure I don't make a mistake, I'll get 3 points. We know the graph is a straight line. If then lies on the line. If then lies on the line. If then lies on the line. The graph is shown below.