(2-3/4×4/5)÷(1/12+4/15)简算!今天就要!

问题描述:

(2-3/4×4/5)÷(1/12+4/15)简算!
今天就要!

车2小时行了90千米,那么如果行驶3小时可

(2-3/4×4/5)÷(1/12+4/15)
=(2-3/5)÷(5/60+16/60)
=7/5÷21/60
=7/5x60/21
=12/3
=4