How would you translate this into an equation one third of the number is 12 less than the number itself

How would you translate this into an equation one third of the number is 12 less than the number itself?

Let the number be x. We have:

(1/3)x=x-12

let x be the money she spent so that she can earn the free t-shirt.

since, she already spent $112.49

⇒

also, as per the statement: jennifer must spend $250 or more in order to qualify for a free t-shirt at the store.

then,

we have an inequality i.,e

subtract 112.49 from both sides we get;

therefore, $137. 51 more money does jennifer need to spend so that she can earn the free t-shirt