a + 9 × ( 7 + 2 ) = 109 + 8 × 9
a + 9 × 9 = 109 + 72
a + 81 = 181
a = 181 - 81
a = 100
a - ( 133 - 8 × 9 ) = 3 × 9 + 4 × 9
a - ( 133 - 72 ) = 27 + 36
a - 61 = 63
a = 63 + 61
a = 124
456 - ( 214 + 9 × 7 ) - a = 6 × 9
456 - ( 214 + 63 ) - a = 54
456 - 277 - a = 54
179 - a = 54
a = 179 - 54
a = 125
9 × 5 + 8 × 8 + a = 214
45 + 64 + a = 214
109 + a = 214
a = 214 - 109
a = 105
