Answer:
$128
Step-by-step 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.