可汗学院
6. Which of the following equations represents a line in the xy-plane with an x-intercept at (-2, 0) and a slope of 4?
A. y=4x+8
B. y=-4x+8
C. y=4x-2
D. y=-4x-2
Correct Answer: A Difficult level: 2
8. The equation y=x+a is graphed in the xy-plane, where a is a positive constant. A second equation, y=x-a, is graphed in the same xy-plane. How do the slope and y-intercept of the graph of the first equation compare with the slope and y-intercept of the graph of the second equation?
A. The slopes are the same; the y-intercept of the first equation's graph is the point (0, a), and the y-intercept of the second equation's graph is the point (0, −a).
B. The slopes are the same; the y-intercept of the first equation's graph is the point (0,-a), and the y-intercept of the second equation's graph is the point (0, a).
C. The y-intercepts are the same; the slope of the first equation's graph is a, and the slope of the second equation's graph is -a.
D. The y-intercepts are the same; the slope of the first equation's graph is −a, and the slope of the second equation's graph is a.
Correct Answer: A Difficult level: 2
9. Which of the following is an equation of the line A graphed in the xy-plane that passes through the point (−1,3.5) and is perpendicular to the line B whose equation is x + 4.5 = 0?
A. x=-1
B. x=3.5
C. y=3.5
D. y=4.5
Correct Answer: C Difficult level: 2
10. A line is graphed as shown BELOW. Which of the following equations represents the line?