Currently working on system of equations. A certain word problem is confusing me.

A school made $1220 on its fundraiser by washing cars and recycling can.

Students were paid an average of $55 per car wash, and 35 for picking up cans.

There are four less people washing cars than picking up cans.

Write a system of equations to determine how many car washers there are.

Let x=amount of car washers

Let y= amount of can pickers

four less people washing cars than picking cans,

Account for the "how much school made":

and by substitution,