Question

question 4 of 10
which of the following are the correct properties of slope?
check all that apply.

a. if two lines have the same slope, then they are the same line.

b. a steep line has negative slope.

c. the slope of a line that moves up from left to right is positive.

d. some lines have an undefined slope.

e. the slope of a line is always positive.

Explanation:

• Option A: Lines with the same slope are parallel, not necessarily the same line (they could have different y - intercepts), so A is incorrect.
• Option B: A steep line can have a positive or negative slope (steepness is about the magnitude of the slope, not the sign), so B is incorrect.
• Option C: By the definition of slope (rise over run), if a line moves up from left to right, the rise is positive and the run is positive, so the slope (rise/run) is positive. This is correct.
• Option D: Vertical lines have an undefined slope (since the run is 0 and division by 0 is undefined), so some lines (vertical lines) have an undefined slope. This is correct.
• Option E: Slopes can be negative (for lines that go down from left to right), zero (for horizontal lines), or undefined (for vertical lines), so slopes are not always positive. E is incorrect.

Answer:

C. The slope of a line that moves up from left to right is positive.
D. Some lines have an undefined slope.