Question

Which points are on the line given by the equation y = -5x + 3? (-2,7) (2,-7) (-1,8) (4,-23)

Answer 1

Plug in the values for x and y and see if the set of points matches the equation

Answer 2

For the first set of points, you would have 7 = -5(-2) + 3
7 = 10 + 13 // not on the line

Answer 3

y = -5(2) = 3
-7 = -10 + 3 = -7 // on the line
can you do the rest?

Answer 4

@santiej, that help?

Answer 5

Yes, it does.

Answer 6

But how do I know if the point that I get is on the line?

Answer 7

You know by if y satisfies the equation for the points

Answer 8

That is why we plugged in a set of points and checked to see if it was on the line or not

Answer 9

If it doesn't satisfy the equation, it is not on the line

Answer 10

does that make sense?

Answer 11

Not really.

Answer 12

How do I know if the equation is satisfied?

Answer 13

So let's take the first point: (-2, 7), when we plug in 7 for y and -2 in for x, if the two equal each other then that point is on the line

Answer 14

That might help you to understand

Answer 15

So, if y and x are equal then I know it is on the line?

Answer 16

correct

Answer 17

Ok, thank you.

Answer 18

because it satisfies the equation

Answer 19

Thank you for taking the time to help me.

Answer 20

Np. I'm glad you got it. :)