6a+13a 6x-28-2.5x+30.5 8a-(5a+8a) (5x+7-(4x+0)
=19a =3.5x+2.5 =3a+8a =1x+7.18
6x-28-2.5x+30.5
解:(6-2.5X)-28+30.5
3.5X-28+30.5
3.5X-58.5
6x-28-2.5x+30.5=3.5x+30.5
(6-2.5)x-28+30.5
(6+13)a
(8-5)a+8
(5-4)x-(7-0.18)
805x-28+30.5
19a
3a-8
x-7.18
6x-28-2.5x+30.5
=(6x-2.5x)-(30.5-28)
=3.5x-12.5