[(1 + 2) x 3 - 4 ]÷ 5 = 1[1 x( 2 + 3 )- 4 + 5] ÷ 6 = 1[(1 + 2 )x 3 ÷ (4 + 5 )+ 6 ]÷ 7 = 1[(1 + 2 )÷ 3 x 4 + 5 + 6 - 7 ]÷ 8 = 1(1 x 2 + 3 + 4 - 5 + 6 + 7 - 8 )÷ 9 = 1
