2x – 5) + 17 = 6 
(=) 2 x-5= 6 -17= -11
(=) 2x= -11+5=-6
(=) x= -3

a) (2x – 5) + 17 = 6      
<=> 2x = -6
<=> x = -3
vậy x = -3     
b) 10 – 2(4 – 3x) = -4
<=> 10 - 8 + 6x = -4
<=>  6x = -6
<=> x = -1 
c) - 12 + 3(-x + 7) = -18
<=> 3x = 27
<=> x = 9
d) 24 : (3x – 2) = -3 
<=> 24 = -3(3x - 2)
<=> 24 = -9x + 6
<=> 9x = -18
<=>  x=-2          
e) (x+5) . (x – 4) = 0 
<=> x= -5 or x = 4          
g ) 2 - 59 = - 21 (???)