sat-dog

The correct answer is 74. The y-intercept of a line in the xy-plane is the ordered pair of the point of intersection of the line with the y-axis. Since line k intersects the y-axis at the point , it follows that is the y-intercept of this line. An equation of any line in the xy-plane can be written in the form , where m is the slope of the line and b is the y-coordinate of the y-intercept. Therefore, the equation of line k can be written as , or . The value of m can be found by substituting the x- and y-coordinates from a point on the line, such as , for x and y, respectively. This results in . Solving this equation for m gives . Therefore, an equation of line k is . The value of w can be found by substituting the x-coordinate, 20, for x in the equation of line k and solving this equation for y. This gives , or . Since w is the y-coordinate of this point, .