The graphs of the three equations are:

y = x^2 - 3 is a parabolic curve that opens upwards with a vertex at (0, -3).

y = (x-3)^2 is a parabolic curve that opens upwards with a vertex at (3, 0).

y = -(x-3)^2 is a parabolic curve that opens downwards with a vertex at (3, 0).

To solve the expression (7/6 + 3 4/9) * 4.5, first convert the mixed number 3 4/9 to an improper fraction:

3 4/9 = 3 + 4/9 = 27/9 + 4/9 = 31/9

Now add 7/6 and 31/9:

(7/6 + 31/9) = (21/18 + 31/9) = (14/12 + 31/9) = (126/108 + 124/108) = 250/108

Finally, multiply the sum by 4.5:

250/108 4.5 = 250 4.5 / 108 = 1125 / 108 = 125/12

Therefore, (7/6 + 3 4/9) * 4.5 equals 125/12.