若2m=3,2n=2,则2m+2n=()
(1)解方程:9﹣3y=5y+25 (2)计算:(﹣3)3÷×(﹣)2﹣2×(﹣)
计算: (1)-9+12-3+8; (2); (3); (4)21×(-0.75)-105×+14÷.
计算: (1) (2)
计算: (1) (2) (3) (4)
计算: (1) (2) (3) (4) (5) (6)
计算:(每题4分,共16分) (1)﹣20+(﹣15)﹣(﹣28)﹣17 (2) (3) (4).
(1) (2)
计算: (1)3—4.3—7+5.3; (2); (3); (4).
计算: (1)(﹣4)﹣(﹣1)+(﹣6)÷2. (2)27÷(﹣3)2﹣(﹣)×(﹣8)
计算:(﹣4)2+(π﹣3)0﹣23﹣|﹣5|.
计算下列各题: (1) (2) (3), (4)
计算 (1) (2) (3) (4) (5) (6)19×(-12)
计算(每题5分,共30分) (1) (2) (3) (4) (5) (6)