Respostas

2013-12-26T16:55:03-02:00
2013-12-26T18:25:45-02:00
7x+8-9z[(243x +089)]-660
7x+8-(2187zx+801z)-660
7x+8-2187zx-801z-660
7x -2187xz-801z-660+8
-2187xz+7x+801z-652
X=(-2187xz+801z-652):7