- 1/4X +18 = 1+ 20%X
-x+72=4+0.8x
0.8x+x=72-4
1.8x=68
x=340／9是X - 1/4X +18 = 1+ 20%XX - 1/4X +18 = 1+ 20%X¾x＋18＝1＋0.2x0.55x=-17x=-340／11