4/5X(-5/13)-(-3/5)X-5/13X(-3/15)等于多少

问题描述:

4/5X(-5/13)-(-3/5)X-5/13X(-3/15)等于多少

=(-4/13)X+(3/5)X+(1/13)X
=(-20/65)X+(39/65)X+(5/65)X
=(24/65)X
=8/15X