4/5*(-5/13)-(-3/5)*(-5/13)-5/13*(-8/5) 用乘法分配律逆向应用

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4/5*(-5/13)-(-3/5)*(-5/13)-5/13*(-8/5) 用乘法分配律逆向应用
4/5*(-5/13)-(-3/5)*(-5/13)-5/13*(-8/5) 用乘法分配律逆向应用

4/5*(-5/13)-(-3/5)*(-5/13)-5/13*(-8/5) 用乘法分配律逆向应用
原式=4/5×(-5/13)-(-3/5)×(-5/13)-5/13×(-8/5)
=4/5×(-5/13)-(-3/5)×(-5/13)-8/5×(-5/13)
=[4/5-(-3/5)-8/5]×(-5/13)
=(4/5+3/5-8/5)×(-5/13)
=(4+3-8)/5×(-5/13)
=(7-8)/5×(-5/13)
=[-(8-7)]/5×(-5/13)
=(-1/5)×(-5/13)
=1/5×5/13
=1/13

4/5×(-5/13)-(-3/5)×(-5/13)-5/13×(-8/5)
=4/5×(-5/13)-(-3/5)×(-5/13)-8/5×(-5/13)
=[4/5-(-3/5)-8/5]×(-5/13)
=(4/5+3/5-8/5)×(-5/13)
=(4+3-8)/5×(-5/13)
=(7-8)/5×(-5/13)
=[-(8-7)]/5×(-5/13)
=(-1/5)×(-5/13)
=1/5×5/13
=1/13