Answer:
$128
Explanation:
Given: Nghiep gave half of his weekly salary to his mother.
Spent remaining half on a new shirt.
Finally he is left with $32
Lets assume Nghiep´s weekly earning be "x".
As given, Nghiep gave his mother half of weekly earning.
∴ Remaining earning= 
Taking LCD as 2
⇒ Remaining earning= 
Hence, remaining salary giving half earning to his mother is 
Now, as given Nghiep spent half of what was left on a new shirt.
∴ Amount spent on shirt= 
Next, finding the amount left with Nghiep after spending on shirt.
⇒ Amount left after spending on shirt= 
taking LCD as 4
⇒ Amount left after spending on shirt= 
As given, Nghiep left with $32 after spending on shirt.
∴ We can form an equation for amount left with Nghiep after spending on shirt.
⇒
Now, solving it to find the weekly earning of Nghiep.
⇒ 
Multiplying both side by 4.
⇒
∴ 
Hence, Nghiep´s weekly earning is $128.