用竖式计算并验算.⑴5.84+26.36= ⑵10.25﹣9.68= ⑶20﹣12.39= ⑷15.8+16.28=
列竖式计算42.36÷66÷0.9(保留两位小数)0.51÷0.5.
解方程 9x﹣6x=7.2 19.76÷x=3.8 1.16+2.6x=12.86 (x﹣6)×50=125 22x+1.7×5=52.5 4x+(12﹣x)×2=44.
简便计算 0.49×12.5×0.8; 5.61﹣5.61÷1.5; 0.45×78.2+20.8×0.45+0.45.
竖式计算0.56×7.2=2.46÷8.2=5.202÷0.51=
口算: