Question

Which ordered pairs from the replacement set are solutions to the equation?

y = -2x + 9 ; Replacement Set {((-1, 11), (0, 8), (1, 7), (2, 5)}

(-1, 11)


(0, 8)


(1, 7)


(2, 5)

Answer 1

Each ordered pair is of the form:\[(x _{1}, y _{1})\]You take each ordered pair and substitute like so:\[y _{1} = -2x _{1} + 9\]and see if it is true. You do this for each ordered pair, one at a time and test it.

For your first ordered pair, the x1 = -1 and the y1 = 11. So, you can test the first one by substituting those values.

Answer 2

So you ask yourself if:

11 = -2(-1) + 9

is true or not.

Answer 3

What is -2(-1) ? Hint: that is -2 times -1

Answer 4

2

Answer 5

so -1,11 works

Answer 6

To perform multiplication with negative signs, you first multiply the numbers and then if the number of "-" signs is an even number, you have a positive result.

Just saw your answer, so you probably already understand this. Good. So, continuing:

11 = -2(-1) + 9 -> 11 = 2 + 9

Yes, you already saw now that it works.

Good job. Now just check the other 3 ordered pairs. Hint: only one doesn't work.

Answer 7

ok thanks:)

Answer 8

So, this is making sense to you now?

Answer 9

yes it is I just needed a refresher

Answer 10

I'm glad you're getting this. It's a great feeling when understanding comes. It's like a gift.

Answer 11

Good luck again and thx for the recognition!