计算下列各题:(1)23-17-(-7)+(-16)(2)(?81)÷94×49÷(?16)(3)(?114+58?712)×(?24)(4)?14?

2024-11-20 18:42:29
推荐回答(1个)
回答1:

(1)原式=23-17+7-16
=(23+7)-(17+16)
=30-33
=-3;
(2)(?81)÷

9
4
×
4
9
÷(?16)
原式=(?81)×
4
9
×
4
9
÷(?16)

=1;
(3)(?1
1
4
+
5
8
?
7
12
)×(?24)

原式=?
5
4
×(?24)+
5
8
×(?24)?
7
12
×(?24)

=30-15+14
=29;
(4)?14?(1?0.5)×
1
3
×[2?(?3)2]

原式=?1?
1
2
×
1
3
×(2?9)

=-1-
1
6
×(?7)

=
1
6

(5)3x2+2xy-4y2-3xy+4y2-3x2
原式=(3x2-3x2)+(2xy-3xy)+(-4y2+4y2
=-xy.