b² - 16a + 6
(7)² - 16(1/2) + 5
49 - 8 + 5
49 -13
36
-------------------------------
3b - 2a - 9
3(7) - 2(1/2) - 9
21 -1 - 9
20 - 9
11
-------------------------------
16a - b
16(1/2) - 7
8 - 7
1
-------------------------------
3(7) - 2(1/2) - 9
21 -1 - 9
20 - 9
11
-------------------------------
6(1/2)(7)
3(7)
21
-------------------------------