<解法Ⅱ>
+ B = (3-√7) + (3 + √5) 2-B = = 2√√5
Sd
2ß = ² (3-√5) (3 + √5)
d B
=9-5=4
f(d) - fle) = (d³-92² +12d=-1) - (B³-9P+ 12 B-17)
= 2³ - ß³ - 9 (d ² + 3²) + 12 (d-ß) a
G
(d^ß)³ +3dB(A-B) - g {(a + B) ² - 22 µ} + 12 [d - A)
+3.4(-2)-9(36-24] +121-2.5)
(-215)3
45x (-2√5) - 24 √5 - 9 * 28 - 24 √5
- 40√S-24√s - 252-24 √5
= -88 √5-252.