Explain the significance of the equation y = 50x + 20 which represents the hourly cost of a car repair.

X is amount of hours

y is a cost of repair which depends on amount of hours

for example: Car was repaird by 2 hours, so x=2 and cost of repair is y=50*2+20=120

The '20' is what it costs you to drive your car into the garage and say "Good morning", before they ever start working on it. As you can see, the cost (y) is 20 even if the number of hours (x) is zero.

The '50' is the added cost for each hour a mechanic spends working on the car.