Subscribe

Grade 9 · Math · Unit 3 of 7

Linear Relations

Slope, intercepts and graphs

What your child practises

Finding slope from points and graphs, reading y = mx + b, finding intercepts, deciding whether a point is on a line, spotting parallel lines, and using rates of change in stories.

Nova Scotia Curriculum learning outcome: PR01, PR02 · linear relations: tables, graphs and equations

How we explain it

Children can open this short lesson before they practise.

  1. A line has the equation y = mx + b.
  2. The slope m is rise ÷ run. The y-intercept b is where the line crosses the y-axis.
  3. Find the slope from two points on the line.

Example: A line goes through (0, 1) and (2, 5). What is its slope? Rise: 5 − 1 = 4. Run: 2 − 0 = 2. Slope: 4 ÷ 2 = 2. Answer: 2 (so y = 2x + 1)

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    What is the slope of the line through (0, 0) and (1, -3)?

    -5-5-4-4-3-3-2-2-1-1001122334455AB

    answer box

  2. Question 2

    Find the slope of the line through (1, 3) and (5, 2).

    -5-5-4-4-3-3-2-2-1-1001122334455AB
    • -4
    • 4
    • -1/4
    • 1/4

  3. Question 3

    What is the y-intercept of y = 5x + 4?

    answer box

  4. Question 4

    Which equation has slope 6 and a y-intercept of 2?

    • y = 6x − 2
    • y = -6x + 2
    • y = 6x + 2
    • y = 2x + 6

  5. Question 5

    Is the point (5, 24) on the line y = 4x + 4?

    • Yes
    • No

  6. Question 6

    What is the x-intercept of y = 3x − 21?

    answer box

More Grade 9