Answer: Please see explanation column for answer.
x= -36
Explanation:
Step 1
from the attachment, Mai's solving is given as
1/3 (1/2x- 9) = 1/2 (x+18)
1/6x-3= 1/2x+9
1/4x-3=9
1/4x=12
x=48
Mai's error started when he subtracted wrongly 1/2 x from 1/6x which gave him 1/4 x instead of - 1/3 x.
Solving correctly, we have that
1/3(1/2x-9) = 1/2(x+18)
1/6x -3= 1/2x+ 9
taking like terms to like terms
1/6x-1/2x= 9+3
(1-3)/6x= 12
-2/6x= 12
-1/3x= 12
multiplying both sides by -3
-1/3x X -3 = 12 X -3
x= -36