Think of a vertical number line. The positive values count down as we move down this number line. The negative numbers count up, so to speak, as we move down the number line. So we have -1, -2, -3, ... as we move down. This indicates that -5 is <u>not</u> smaller than -7.
Diagram is below.
Two lines are perpendicular between each other if their slopes fulfills the following property
where m1 and m2 represents the slopes of line 1 an 2, respectively.
To find the slope of a line we can write it in the form slope-intercept form
Our original line is
Then its slope is
Now we have to find the slope of the second line. Using the first property,
Then the second line has to have a slope of 8.
The options given to us are:
Then we have to determine which of these options have a slope of 8. To do that we write them in the slope-intercept form:
Once we have the options in the right form, we note that the only one of them that has a slope of 8 is the last one.
Then the line perpendicular to the original one is