Question

If someone can pls give the answer with steps that would be greatly appreciated :)

Answer 1

8) D

To find the slope of a line that is perpendicular to another, take the slope and do the negative reciprocal. That is, flip the fraction and make the sign opposite.

9) C

Do the negative reciprocal of -4 to find the slope. It is 1/4. So it's either A or C. Then plug in the point (4, -1) to A and C and see which equation works. C works because you get -1 = 1/4 (4) - 2, which simplifies to -1 = 1 - 2, which simplifies to -1 = -1, which is true. When doing that for A, you get -1 = 1, which is wrong.

Answer 2

D

C

Explanation:

One equation must have a slope that is the negative reciprocal of the other equation's slope.

The the sentence I've given you is correct, it is probably a little difficult to understand. Let's use an example

y = 1/2 x + 4

The slope of this line = 1/2

Therefore if you want a negative reciprocal, it would - 2 so y=-2x would be perpendicular to y = 1/2x + 4.

Just to be sure you understand, I'll put the graph of these two equations below.

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So to answer your question

8)

is D. All the others have signs that are the same. They are reciprocals but with signs the same.

9) This is a little harder. You have reciprocals in all of them. But the slope must be positive. So that means that only a and c can be true. A does not go through (4,-1). C does.

y = 1/4 * 4 - 2

y = 1 - 2

y = - 1

So the answer is C