Property used in the equation 9+3+1

That is the associative property.  In addition, it doesn't matter what order you add things in, so you can "associate" any grouping of additions and get the same result:

(a+b)+c = a+(b+c)

Note that this is true for multiplication as well:

(a*b)*c = a*(b*c)

deez nu tz

step-by-step explanation:

step-by-step explanation:

y = | -2(-2) |     →     y = | 4 |     →     y = 4       ⇒   (-2, 4)

y = | -2(-1) |     →     y = | 2 |     →       y =   2       ⇒   (-1, 2)    

y = | -2(0) |     →     y = | 0 |     →       y = 0         ⇒   (0, 0)

y = | -2(1) |   c →     y = | -2 |     →     y =   2         ⇒   (1, 2)    

y = | -2(2) |     →     y = | - 4 |     →     y =   4         ⇒   (2, 4)