\(720:\left[40-\left(2x-5\right)\right]=8.5\\ 720:\left[40-\left(2x-5\right)\right]=40\\ 40-\left(2x-5\right)=18\\ 2x-5=40-18\\ 2x-5=22\\ 2x=27\\ x=\dfrac{27}{2}\)
720 : [ 41 - ( 2x - 5 ) ] = 23 . 5
720 : [ 41 - ( 2x - 5 ) ] = 8 . 5
720 : [ 41 - ( 2x - 5 ) ] = 40
[ 41 - ( 2x - 5 ) ] = 720 : 40
[ 41 - ( 2x - 5 ) ] = 18
( 2x - 5 ) = 41 - 18
2x - 5 = 23
2x = 23 + 5
2x = 28
x = 28 : 2
x = 14