1)12（2-3X）=4X+4 24-36X=4X+4 -40X=-20 X=1/2 (2)6-3（X+2/3）=2/3 6-3X-2=2/3 -3X=-10/3 X=10/9 (3)2（200-15X）=70+25X 400-30X=70+25X -55X=-330 X=6 (4)3（2X+1）=12 6X+3=12 6X=9 X=3/2 (5)1/4X-1/2=...