(1)计算:|-3|-64×(π-3)0+cos60°+(-12)-2;(2)先化简,再求值:(3a+1-a+1)÷a2?4a+4a+1,其

2025-08-10 00:04:13
推荐回答(1个)
回答1:

(1)原式=3-8×1+

1
2
+4
=-
1
2


(2)原式=[
3
a+1
-
(a+1)(a?1)
a+1
]?
a+1
(a?2)2

=
(2+a)(2?a)
a+1
?
a+1
(a?2)2

=
2+a
2?a

当a=-3时,原式=
2?3
2?(?3)
=-
1
5