\(\left(37+13\right)+\left(13-13\right)+\left(12-12\right)\\ =50\)
37 - 13 + 13 -12 + 12 +13
=(37+13)+(13-13)+(12-12)
=50
37 - 13 + 13 - 12 + 12 + 13 = ( 37 + 13 ) + ( 13 - 13 ) + ( 12 - 12 )
= 50
37 - 13 + 13 - 12 + 12 + 13
= ( 37 + 13 ) + ( 13 - 13 ) + ( 12 - 12 )
= 50 + 0 + 0
= 50
37 - 13 + 13 - 12 + 12 + 13
= ( 37 + 13 ) + ( 13 - 13 ) + ( 12 - 12 )
= 50 + 0 + 0
= 50