1/105÷【1/7-91/3)-1/5】=1/105*7+1/105*3-1/105*5=1/15+1/35-1/21哪里错了1/105÷【1/7-(-1/3)-1/5】=1/105*7+1/105*3-1/105*5=1/15+1/35-1/21=1/21哪里错了

问题描述:

1/105÷【1/7-91/3)-1/5】=1/105*7+1/105*3-1/105*5=1/15+1/35-1/21哪里错了
1/105÷【1/7-(-1/3)-1/5】=1/105*7+1/105*3-1/105*5=1/15+1/35-1/21=1/21哪里错了