It is given in the question that
You are buying a new printer and a new scanner for your computer and you cannot spend over $150. The printer you want costs $80.
Let the price of scanner be $ x .
So we have

Subtracting 80 from both sides

It means , the price should be not more then $70 .
Therefore in case, the price of scanner is $75, then you will not remain within your budget .