If AB is parallel to CD and the slope of AB is -3, what is the slope of CD

-3

Step-by-step explanation:

The slopes of parallel lines are equal.

If two lines are parallel (that means they are at the same angle, they are always the same distance apart and they never cross), then they have the same slope. Both lines have slope -3

-3

Step-by-step explanation:

There is a rule in math that if two slopes are parallel, they must have the same slope. Let's answer the question with this first.

So AB is parallel to CD, meaning they must have the same slope. If AB's slope is -3, then so must CD's. That's the answer to the question.

Coming back to the parallel slope rule, why does this work? Well, if two lines are parallel, it means they never will touch each other, meaning they rise, fall, bend, curve, etc... at the same rate. The slope is the change in how much the line rises divided by the change in how much it runs (moves horizontally). That proves the rule.

Please consider a brainliest, thank you!

answer: 21$

step-by-step explanation:

$42 / $14 = 3   (ratio 3: 1)

$7 x 3 = $21

astronomers is your final answer! : )