1. |-6又2/3|*1/4/（（-2/5）*2）=-25/12
2. （3/4）*（-7）-（-15）*(1又3/4)-0.75*2
=-21/4+105/4+3/2
=39/2
3. (-1)^50次方+(-2)^3次方+(-1/2)^5次方+(-1)^7次方
=1+(-8)+(-1/32)+(-1)
=-257/32
4解 0.8+300-0.6x=350
x=82
5.{x>-2
{x≤4/9 所以-2＜x≤4/9 整数解为 -1 0
6. ｛ -6x+5y-3z=-4 .①
｛ 6x-3y+z=8 .②
｛ 6x+y+4z=9 .③
①+② 得2y-2z=4 即 y-z=2 .④
③-② 得4y+3z=1 .⑤
④*4-⑤ 得-7z=7 即z=-1
将z代入④中 得y=1
将y,z代入①中 得x=2
7.4/{(2+3)/(2+3+4)-[4/(2+3+4)]}=36厘米
8.1/[1/8+(1/5-1/8)+(1/4-1/8)]=40/13
9.解设一班有x人
[(95-x)*90％+71％x]/95=81％
解得 x=45 95-45=50
一班有45人 二班有50人
10.末尾有7个零
10*20*30就有3个0 2*5有1个0 4*15有1个0 8*25有2 个0
所以一共7个
英语
1. Her mother was cooking in the kitchen
2.No,they weren't.
3.Half past seven
4.They gave some flowers to Jane
5.Yes,they did
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