Question

Which coordinate pairs make the equation x-9y=12 true?

1. (12,0)
2. (0,12)
3. (3,-1)
4. (0, -4/3

Answer 1

(12,0) and (3, -1) and (0,-4/3)

Explanation:

To find if a point makes an equation true, just substitute its x and y values in in the equation and simplify.

1) Let's test the point (12,0). Substitute 12 for x and 0 for y in the equation:

`x-9y=12\\(12)-9(0)=12\\12-0=12\\12=12`

12 does equal 12, so (12,0) makes the equation true.

2) Let's test the point (0, 12). Substitute 0 for x and 12 for y in the equation:

`x-9y=12\\(0)-9(12) = 12\\0-108 = 12\\-108 = 12`

However, -108 does not equal 12, so (0,12) does not make the equation true.

3) Let's test the point (3, -1). Substitute 3 for x and -1 for y in the equation:

`x-9y=12\\(3)-9(-1) = 12\\3 + 9 = 12\\12 = 12`

12 does equal 12, so (3, -1) makes the equation true.

4) Let's test the point (0, -4/3). Substitute 0 for x and -4/3 for y in the equation:

`(0) -9(-(4)/(3) ) = 12\\0 + (36)/(3) = 12\\0 + 12 = 12 \\12 = 12`

12 does equal 12, so (0, -4/3) makes the equation true.