Question #N728
The graph of the line is shown below. Which of the following is the equation of this line? \begin{align*} \text{A. } y&= -2x - 8\ \text{B. } y&= x - 8\ \text{C. } y&= -x - 8\ \text{D. } y&= 2x - 8\ \end{align*}
A. y = -2x - 8
B. y = x - 8
C. y = -x - 8
D. y = 2x - 8
Correct Answer is: C
The equation of a line can be written in slope-intercept form: y = mx + b, where m is the slope of the line, and b is the y-intercept of the line. The line shown passes through the point (-8, 0), so b = 0. The line shown also passes through the point (-1, 8). The slope, m, of a line passing through two points and can be calculated using the equation . For the points and , this gives , or . Substituting for m and for b in y = mx + b yields y = -x + 0, or y = -x. Therefore, an equation of the graph shown is y = -x - 8.