Tracie and Marcia drove to Northern California to see Marcia’s sister in Eureka. Tracie drove one hour more than four times as much as Marcia. The trip took a total of 21 driving hours. How many hours did Tracie drive?

The variable z is directly proportional to x, and inversely proportional to y. when x is 4 and y is 13, z has the value 1.2307692307692. what is the value of z when x= 9, and y= 20

Can someone me with my hwplz(only the circled ones)

Aformual for 8 bottles of window cleaner calls for 6 cups of rubbing to customers alcohol 2 1/4 gallons of water and 1 1/2 cups of ammonia alcohol would the forula call if a factory made 1,280 bottles for stores to sell to customers