X and Y Intercept Practice

Question Icon

Question 1

Find the x & y intercepts for the following linear equation:

y = -3x + 9

Extra: Try to draw the line of y = -3x + 9 after finding the x and y intercepts.

Answer

Answer Icon

Select and check your answer...

A. y-intercept = 3 & x-intercept = -9
B. y-intercept = 3 & x-intercept = 9
C. y-intercept = 9 & x-intercept = 3
D. y-intercept = 9 & x-intercept = -3

Step by Step Solution

  • Lesson Icon

    Step 1

    Let's find the y-intercept. From the lesson, we know that the y-intercept is the y-coordinate of a point where the line crosses the y-axis.

    0 = x-coordinate
    y = y-coordinate = y-intercept

    Now, we can solve for the y-intercept:

    negative slope

    From the calculation above, we have the y-intercept as 6.

    Finding the y-intercept
  • Lesson Icon

    Step 2

    As for the x-intercept, we know that the x-intercept is the x-coordinate of a point where the line crosses the x-axis.

    Therefore, let's imagine the coordinate of that point is (x,0), where:

    x = x-coordinate = x-intercept
    0 = y-coordinate

    So, now we can solve for the x-intercept:

    negative slope

    From the calculation above, we have the x-intercept as 3.

    Finding the x-intercept
  • Lesson Icon

    Step 3

    To summarize, we have:

    y-intercept: 9
    x-intercept: 3

    With these intercepts, we have 2 points with the coordinates:

    (0.0,9.0)

    (3.0,0.0)

    Hence, by plotting these 2 points on the graph, we are able draw the line of y= -3x + 9 as shown in the picture.

    graph of y = -3x + 9
  • Lesson Icon

    Step 4

    With the y-intercept as 9 and x-intercept as 3, the answer is C.