竖式计算72÷6=验算 83÷4=验算
求x的值:5:x=1.
计算 1.25﹣(+)×80%
计算:6×﹣5×.
解方程:2+1.8﹣5ⅹ=3.62ⅹ÷2.3=4.50.2(5x﹣1)+5(x﹣1)="0.8" 7(ⅹ﹣1.2)=2.1.
简算4.9+0.1﹣4.9+0.110.78﹣(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.