问题
解答题
(1)(
(2)已知:a=2+
|
答案
(1)原式=(
×1 3
-72 2
)-(9×3
-2×3 9
)2 4
=
-72 6
-3
+3 2 2
=
-82 2 3
;3
(2)∵a2+b2+ab=(a+b)2-ab,
∴原式=42-(2+
)(2-3
)=16-4+3=15.3
(1)(
(2)已知:a=2+
|
(1)原式=(
×1 3
-72 2
)-(9×3
-2×3 9
)2 4
=
-72 6
-3
+3 2 2
=
-82 2 3
;3
(2)∵a2+b2+ab=(a+b)2-ab,
∴原式=42-(2+
)(2-3
)=16-4+3=15.3