Your friend has $100 when he goes to the fair he spends 10 to interfere in 20 on food Rides at the fair cost two dollars per ride which function can be used to determine how much money he has left over after x rides

$70-$2x

Step-by-step explanation:

In the beginning, your friend spent $30 on interference and food, leaving him or her $70.

Since every ride costs $2, you multiply the amount of rides he rode by 2 to get how much he spent.

He subtracted that from the money he had which was $70.

Therefore, the equation is $70 - $2x