Answer:
x + y are either 2 or 4
Step-by-step explanation:
conclusion x + y = 2 OR 4
You should try reading notes you took during your class period.
Well, their speeds are (

is Jack's speed, and

is Richard's.

They, together, can paint 12 houses in 35 days. To get a single house, we only have to calculate

which is very close to 3 (a bit below)