When rolling two standard six-sided dice, what is the probability that the sum of the dice will be even or a multiple of 3? (show your work)

2/3

Step-by-step explanation:

List all the possible sums.  If it helps, make a table:

There are 36 total possible sums.  Of those, 18 are even, and 6 are odd but multiples of 3.

Therefore, the probability is:

P = (18 + 6) / 36

P = 24 / 36

P = 2 / 3

so part 1: the y values stay the same, but the x values are opposite signs.

part 2 & 3: the line will be of equal lengths and will be straight.

part 4: you'd see the same characteristic because the x coordinate becomes a negative making them at equal distances from the y axis?