赖梅回答:
(2x)³-(3y)³=8x³-27y³
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找出成语中意思相对的词.七上八下,声东击西,一来二去,走南闯北,一张一弛,千山万水,九死一生,弃暗投明,五湖四海,口是心非,头重脚轻,
1,2,3,4,5,6,7,8,9,10,11,12在前面添上正负号使和为零
如图,在直角坐标系中,已知点A(x1,-3)在第三象限,点B(X2,-1)在第四象限,线段AB与y轴交于点D,且∠AOB=90°1当x2=1,求直线AB的解析式2当△AOB的面积等于9时,设∠AOD=α,求sinα*cosα的值.
they,a,that,siad,built,year,hospital,before,they,the,last连词组句