用简便方法算1.25×（0.8+0.4）=? 4.89×99+4.89= ?
问题描述：
用简便方法算1.25×（0.8+0.4）=? 4.89×99+4.89= ?
脱式计算,能简的要简算（14.7+5.6）÷7=?46÷0.8-20.8=? 急!急!急!急!急!急!急!急!急!
答
1.25×（0.8+0.4）=1.25×0.8+1.25×0.4=1+0.5=1.54.89×99+4.89=4.89×（99+1）=489（14.7+5.6）÷7=14.7÷7+5.6÷7=2.1+0.8=2.946÷0.8-20.8这题是46÷0.8-2÷0.8或者46÷0.8-22÷0.8如果是46÷0.8-22÷0.8,那么46...