(1)30﹣7.6= (2)7.8+5.2= (3)23×13=(4)836÷4= (5)38×24= (6)☆422÷7=
计算:6×﹣5×.
解方程: 2+1.8﹣5ⅹ=3.6 2ⅹ÷2.3=4.5 0.2(5x﹣1)+5(x﹣1)="0.8" 7(ⅹ﹣1.2)=2.1.
简算 4.9+0.1﹣4.9+0.1 10.78﹣(2.78+3.693) 99.99×22.22+33.33×33.34 (2.5×2.5+2.5×2.5+2.5×2.5+2.5×2.5)×8.
计算
根据46×15=690,1575÷15=105,直接写出下面各题的结果. 4.6×15= 0.46×0.15= 15.75÷0.15= 15.75÷1.5= .