a) 4x – (- 18) = 42
⇒4x+18=42
⇒4x=24
⇒x=6
b) - 21 – 2(x – 5) = - 37
⇒-21-2x+5=-37
⇒-16-2x=-37
⇒2x=21
⇒x=21/2
c) - 5x + 4 = - 2x + (- 10)
⇒-5x+4=-2x-10
⇒-5x+2x=-10-4
⇒-3x=-14
⇒x=14/3
d) |2x - 1| + (-25) = - 16
⇒|2x - 1|=9
⇒2x-1=9 hoặc 2x-1=-9
⇒x=5 hoặc x=-4
e) - 102 + (x + 6)2 = - 38 : (-6)
⇒-102+(x+6).2=19/3
⇒-102+(x+6)=19/6
⇒x+6=631/6
⇒x=595/6