a , 43 + ( 9 - 21 ) = 317 - ( x + 317 )
b , ( 15 - x ) + ( x - 12 ) = 7 - ( -5 + x )
c , x - { 57 - [ 42 + ( -23 - x )]} = 13 - { 47 + [ 25 - ( 32 - x )]}
d , -7 + | x - 4 | = -3
e , 13 - | x + 5 | = 13
g , | x - 10 | - ( -12 ) = 4
h , | x + 2 | < 5