8th grade Ch 3 L5

Graph the equation y = 3x - 9 on the provided grid.

• The line should pass through the y-intercept at (0, -9) and have a slope of 3 (rise 3, run 1).

• The line should pass through the y-intercept at (0, 9) and have a slope of -3 (fall 3, run 1).

• The line should pass through the y-intercept at (0, -3) and have a slope of 9 (rise 9, run 1).

• The line should pass through the y-intercept at (0, 3) and have a slope of -9 (fall 9, run 1).

Answer explanation

Graph the equation y = (1/2)x + 2 on the provided grid.

• The line should pass through the y-intercept at (0, 2) and have a slope of 1/2 (rise 1, run 2).

• The line should pass through the y-intercept at (0, -2) and have a slope of 2 (rise 2, run 1).

• The line should pass through the y-intercept at (0, 2) and have a slope of -1/2 (fall 1, run 2).

• The line should pass through the y-intercept at (0, -2) and have a slope of -1/2 (fall 1, run 2).

Answer explanation

A store sells juice boxes in packages of 6 boxes and 8 boxes. They have 288 total juice boxes. This is represented by the function 6x + 8y = 288. Use the x- and y-intercepts to graph the equation.

• x-intercept: (48, 0),

  y-intercept: (0, 36).

• x-intercept: (36, 0),

  y-intercept: (0, 48).

• x-intercept: (24, 0),

  y-intercept: (0, 12).

• x-intercept: (12, 0),

  y-intercept: (0, 24).

Answer explanation

Tags

CCSS.HSF-IF.C.7A

The x-intercept and y-intercept can be used to graph a linear equation by:

• Plotting both intercepts and drawing a line through them

• Finding the midpoint between the intercepts

• Using only the x-intercept to draw the line

• Ignoring the intercepts and plotting random points

Tags

CCSS.HSF-IF.C.7A

State the x- and y-intercepts of the equation y = -2x + 7

• x-intercept: (3.5, 0);

  y-intercept: (0, 7)

• x-intercept: (0, 3.5);

  y-intercept: (7, 0)

• x-intercept: (7, 0);

  y-intercept: (0, -2)

• x-intercept: (0, -2);

  y-intercept: (3.5, 0)

Answer explanation

State the x- and y-intercepts of the equation y = (3/4)x + 3. Then use the intercepts to graph the equation.

• x-intercept: (-4, 0); y-intercept: (0, 3)

• x-intercept: (4, 0); y-intercept: (0, -3)

• x-intercept: (0, 4); y-intercept: (3, 0)

• x-intercept: (3, 0); y-intercept: (0, 4)

Answer explanation

Tags

CCSS.HSF-IF.C.7A

State the x- and y-intercepts of the equation 12x + 9y = 15.

• x-intercept: (5/4, 0);

  y-intercept: (0, 5/3)

• x-intercept: (4/5, 0);

  y-intercept: (0, 3/5)

• x-intercept: (3/5, 0);

  y-intercept: (0, 4/5)

• x-intercept: (5/3, 0);

  y-intercept: (0, 4/3)

Answer explanation

The total number of legs, 1,500, on four-legged and two-legged animals in a zoo can be represented by the equation 4x + 2y = 1,500. Find the x- and y-intercepts.

• x-intercept: (375, 0);

  y-intercept: (0, 750).

• x-intercept: (750, 0);

  y-intercept: (0, 375).

• x-intercept: (500, 0);

  y-intercept: (0, 1000).

• x-intercept: (250, 0);

  y-intercept: (0, 600).

Answer explanation

Tags

CCSS.HSF-IF.C.7A

Find the Error Carmen is finding the x-intercept of the equation 3x – 4y = 12. Find her mistake and correct it. (Carmen's work: 3x – 4y = 12, 3x – 4(0) = 12, 3x = 12, x = 12)

• Carmen substituted y = 0 correctly, but solved 3x = 12 as x = 12 instead of x = 4. The correct x-intercept is x = 4.

• Carmen should have substituted x = 0 instead of y = 0 to find the x-intercept.

• Carmen made a mistake by adding 4y instead of subtracting it.

• Carmen should have divided by 4 instead of 3 in the last step.

State the x- and y-intercepts of the equation 2x + 3y = 24.

• x-intercept: (12, 0);

  y-intercept: (0, 8)

• x-intercept: (0, 12);

  y-intercept: (8, 0)

• x-intercept: (8, 0);

  y-intercept: (0, 12)

• x-intercept: (0, 8);

  y-intercept: (12, 0)

Answer explanation