圆有无数条对称轴,且长度相等. .
计算,能用简便计算的用简便计算.8×4×12.5×0.25 8.7×2.9+71×0.87÷[(﹣)×24] (+﹣)×12.
(1)9750÷25+75 (2)(2.32+1.8)×6.5 (3)101×7.8(4)×+ (5)[﹣(+)].
计算下列各题,能简算的要简算.25%×63+37× 101×﹣ 375﹣448÷8×5[75×(6.9﹣3.72)]÷0.6 (+﹣)×36 +(+)÷.
(1):x=2:1.8 (2)[(1.4+1.6×2)×(1÷﹣2.375)]+2.901(3)2007×20082008﹣2008×20072007 (4)++++…+.
下面各题,怎样算简便就怎样算.1080+270÷18﹣864 7.54++2.46+ (2.4﹣)÷0.625+2.5×12.5×40×0.8 6﹣÷﹣ .