136 - a + 14 : 2 = 47
136 - a + 7 = 47
136 - a = 47 - 7
136 - a = 40
a = 136 - 40
a = 96
a - 48 : 6 + 31 = 1 006
a - 8 = 1 006 - 31
a - 8 = 975
a = 975 + 8
a = 983
( 276 - 231 ) : a - ( 253 - 189 ) : 8 = 1
45 : a - 64 : 8 = 1
45 : a - 8 = 1
45 : a = 1 + 8
45 : a = 9
a = 45 : 9
a = 5