七年级上册有理数混合运算专题精选练习 下载本文

(4)(5)(6)

. . .

【解答】解:(1)原式=23﹣22﹣17+6=﹣10; (2)原式=1××=;

(3)原式=﹣9×+10=﹣15+10=﹣5; (4)原式=(﹣

)×(﹣60)=﹣40+5=﹣35;

(5)原式=﹣4﹣4=﹣8; (6)原式=16﹣30+21=7.

14.计算: (1) (2)(3)(4)

【解答】解:(1)原式=﹣﹣﹣=﹣=﹣6

﹣5 ;

(2)原式=(﹣4+16)×(﹣) ==﹣

×(﹣)

(3)原式=﹣1﹣××(﹣7) =﹣1+ =;

(4)原式==

×(﹣5+2﹣6)

×(﹣9)

=﹣30. 15.计算

(1)23﹣17﹣(﹣7)+(﹣16) (2)(﹣4)+|﹣8|+(﹣3)3﹣(﹣3) (3)﹣24÷(2)2﹣3×(﹣) (4)×(﹣2)﹣[4÷(﹣)+1]+(﹣1)

3

2

2008

【解答】解:(1)23﹣17﹣(﹣7)+(﹣16) =23﹣17+7﹣16 =﹣3

(2)(﹣4)+|﹣8|+(﹣3)3﹣(﹣3) =﹣4+8﹣27+3 =﹣20

(3)﹣24÷(2)2﹣3×(﹣) =﹣24×=﹣=﹣

+

=﹣

(4)×(﹣2)3﹣[4÷(﹣)2+1]+(﹣1)2008. =﹣2﹣(9+1)+1 =﹣11 16.计算

(1)22+(﹣4)+(﹣2)+4 (2)(﹣)++(﹣)+ (3)﹣12+15﹣|﹣7﹣8| (4)1(5)(6)﹣14﹣

【解答】解:(1)22+(﹣4)+(﹣2)+4 =22﹣4﹣2+4 =20

(2)(﹣)++(﹣)+ =﹣﹣++ =﹣12+5 =﹣7

(3)﹣12+15﹣|﹣7﹣8| =﹣12+15﹣15 =﹣12 (4)1=1+﹣2+

=2﹣2 =0 (5)

=﹣24×+24×+24× =﹣16+18+4 =6

(6)﹣14﹣=﹣1﹣×(3﹣9) =﹣1+1 =0

17.计算:

(1)12﹣(﹣18)+(﹣12)﹣15 (2)(﹣)﹣(﹣)+(﹣)+ (3)(﹣+)×(﹣24)

(4)﹣14+(﹣2)3×(﹣)﹣(﹣32)

【解答】解:(1)原式=12+18﹣12﹣15=30﹣27=3;

(2)原式=﹣﹣++=﹣1+1=0;

(3)原式=﹣6+12﹣4=2;

(4)原式=﹣1+8×+9 =﹣1+4+9