Quiz Review_Slope & Writing y=mx+b from a Graph

What is the equation of a line with a slope of 4 and a y-intercept of 2?

• y = -4x + 2

• y = -2x + 4

• y = 4x + 2

• y = 2x + 4

Answer explanation

The equation of a line is given by y = mx + b, where m is the slope and b is the y-intercept. Here, the slope is 4 and the y-intercept is 2, so the equation is y = 4x + 2.

Tags

CCSS.8.EE.B.6

CCSS.8.F.A.3

What is the equation of a line when m = -3 and b = 5?

• y = -3x + 5

• y = -3x - 5

• y = 5x + 3

• y = -5x - 3

Answer explanation

The equation of a line is given by y = mx + b, where m is the slope and b is the y-intercept. Here, m = -3 and b = 5, so the equation is y = -3x + 5, which matches the first answer choice.

Tags

CCSS.8.EE.B.6

CCSS.8.F.A.3

What is the equation of this line?

• y = 2x +2

• y = 2x -2

• y = -x + 2

• Cannot be Determined

Answer explanation

The line has a negative slope and a y-intercept of 2. The equation y = -x + 2 matches this description, indicating that for every increase in x, y decreases by the same amount, confirming it as the correct choice.

Tags

CCSS.HSA.CED.A.2

CCSS.HSA.REI.D.10

Write the equation of the line.

• y = -1/3x - 2

• y = 1/3x - 2

• y = 3x - 2

• y = -3x - 2

Answer explanation

The correct equation of the line is y = 1/3x - 2, which has a positive slope of 1/3 and a y-intercept of -2. This indicates the line rises as it moves to the right, matching the characteristics of the given options.

Tags

CCSS.HSA.CED.A.2

CCSS.HSA.REI.D.10

Write the equation of the line.

• y = -2/3x + 4

• y = 2/3x + 4

• y = 3/2x + 4

• y = -3/2x + 4

Answer explanation

The slope of -3/2 indicates a steep decline, and the y-intercept of 4 shows where the line crosses the y-axis. Thus, the correct equation of the line is y = -3/2x + 4.

Tags

CCSS.HSA.CED.A.2

CCSS.HSA.REI.D.10

What is the equation of this line in slope-intercept form?

• y = 2x + 5

• y = -2x + 5

• y = -2x

• y = 5

Answer explanation

The line has a negative slope of -2 and a y-intercept of 5. This matches the equation y = -2x + 5, which is in slope-intercept form (y = mx + b). The other options do not fit these criteria.

Tags

CCSS.HSA.CED.A.2

CCSS.HSA.REI.D.10

CCSS.HSS.ID.C.7

What does "m" represent in y=mx+b?

• y-intercept

• slope

• macaroni

• nothing

Answer explanation

In the equation y=mx+b, 'm' represents the slope of the line. It indicates how steep the line is and the direction it goes. The correct answer is 'slope', not y-intercept, macaroni, or nothing.

Tags

CCSS.8.EE.B.6

CCSS.8.F.A.3

Find the slope of the line.

• 1/2

• -1/2

• 2

• -2

Answer explanation

To find the slope of a line, use the formula (y2 - y1) / (x2 - x1). If the coordinates are (x1, y1) and (x2, y2), substituting the values gives a slope of 1/2, making the correct answer 1/2.

Tags

CCSS.8.EE.B.5

Which graph has a slope of undefined?

• Red

• Blue

• Neither

Answer explanation

The graph with an undefined slope is vertical, which means it does not rise or fall as it moves along the x-axis. The Red graph must be vertical, making it the correct choice for having an undefined slope.

Tags

CCSS.8.EE.B.5

What is the slope of the graph?

• -2

• 2

• 1/2

• -1/2

Answer explanation

The slope of a graph represents the rate of change. A slope of -2 indicates that for every 1 unit increase in x, y decreases by 2 units. Thus, the correct answer is -2.

Tags

CCSS.8.EE.B.5