How many dogs are there in the world?

900 million.

Step-by-step explanation:

It's estimated that there are 900 million dogs in the world, as of 2018.

It's estimated that there are 900 million dogs in the world, as of 2018

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