7.8×1/2÷[1.9-1.9×(1.9-1.9)]用简便方法计算

问题描述:

7.8×1/2÷[1.9-1.9×(1.9-1.9)]用简便方法计算

7.8×1/2÷[1.9-1.9×(1.9-1.9)]
=7.8×1/2÷(1.9-1.9×0)
=3.9÷1.9
=39/19没有简便计算的方法吗?已经最简便了