Is this a function?
(4,12)
(4,15)
(5,18)
(5,21)
(6,24)

No this is not a function.

Step-by-step explanation:

This is not a function because some of the x-values repeat, which is not how a function works. For this to be a function, each x-value would have to be different. In this case, the 4 and 5 repeat in the x-values.

If this answer is correct, please make me Brainliest!

x= -3

step-by-step explanation:

step 1: simplify brackets

4 - x - 1 = 6

step 2: simpilfy

3 - x = 6

step 3: subtract 3 from both sides

-x = 6 - 3

step 4: simpilfy 6 - 3

-x = 3

step 5: multiply both sides by -1

x = -3