Help with 17,18,19,,20 and 21

17.  A positive slope moves upward on a graph from left to right. A negative slope moves downward on a graph from left to right.

18. Zero slope means that the line is horizontal. Just like the line that makes the top of a “Z” is horizontal. No slope means that the line is vertical.

19. Use the slope formula to find the slope of a line given the coordinates of two points on the line. The slope formula is m=(y2-y1)/(x2-x1), or the change in the y values over the change in the x values. The coordinates of the first point represent x1 and y1. The coordinates of the second points are x2, y2.

20. Yes, they did because 2/6 is equivalent to 1/3.

21. A negative slope means that two variables are negatively related; that is, when x increases, y decreases, and when x decreases, y increases. Graphically, a negative slope means that as the line on the line graph moves from left to right, the line falls.

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