sat suite question viewer
The graph shows a linear relationship between and . Which equation represents this relationship, where is a positive constant?
Explanation
Choice C is correct. The equation representing the linear relationship shown can be written in slope-intercept form , where is the slope and is the y-intercept of the line. The line shown passes through the points and . Given two points on a line, and , the slope of the line can be calculated using the equation . Substituting and for and , respectively, in this equation yields , which is equivalent to , or . Since is the y-intercept, it follows that . Substituting for and for in the equation yields . Adding to both sides of this equation yields . Multiplying this equation by yields . It follows that the equation , where is a positive constant, represents this relationship.
Choice A is incorrect. The graph of this relationship passes through the point , not .
Choice B is incorrect. The graph of this relationship passes through the point , not .
Choice D is incorrect. The graph of this relationship passes through the point , not .