7ab+(-8ac)-(-5ab)+10ac-12ab.
化简.要过程..
7ab+(-8ac)-(-5ab)+10ac-12ab.
=7ab-8ac+5ab+10ac-12ab
=7ab+5ab-12ab -8ac+10ac
=2ac
=
7ab+5ab-12ab-8ac+10ac
=
0+2ac
=2ac
够了吧
7ab+(-8ac)-(-5ab)+10ac-12ab
=7ab-8ac-5ac+10ac-12ab
=7ab-(8ac+5ac-10ac)-12ab
=7ab-3ac-12ab
=-3ac-5ab
原式=7ab-8ac+5ab+10ac-12ab=(7ab+5ab-12ab)-(8ac+10ac)=0-18ac=-18ac
