一。3.9x1.4÷0.35二。0.13x102三。0.5x2.33x4四。9.07-22.78÷34 。能用简便算法的要用

3.9x1.4÷0.35=3.9x0.4=(4-0.1)x0.4=1.56
0.13x102=0.13x(100+2)=13+0.26=13.26
0.5x4x2.33=2x2.33=4.66
9.07-22.78÷34=9.07-0.67=8.4