Answer:

Explanation:
We know that Lance wants to buy three sweatshirts and a pair of sweatpants. We then see that sweatpants cost $40.
100 = 40 + 3x
Since Lance has 100 dollars right now, we can erase 40.

Currently, Lance has 60 dollars left.
Since he buys 3 sweatshirts, we have to divide 60 by 3.

Each sweatshirt would cost 20 dollars.