Washing his dad's car alone, eight-year-old levi takes 2.5 hours. if his dad him, then it takes 1 hour. how long does it take levi's dad to wash the car by himself

Levi's dad takes 1.67 hours to wash the car by himself

Step-by-step explanation:

* Lets explain how to solve the problem

- Levi takes 2.5 hours to wash his dad's car alone

- Levi and his dad take 1 hour to wash the dad's car together

∵ Levi takes 2.5 hours to wash the car alone

∴ The rate of Levi is 1/2.5 car/hr

∵ His dad takes x hours to wash the car alone

∴ The rate of his dad is 1/x car/hr

∵ They working together for 1 hour to wash the car

- The equation of the work is rate of Levi × t + rate of his dad × t = 1

∵ t is the time of working together

∵ t = 1 hour

∴

- Multiply both sides by 2.5x to cancel the denominators

∵

∵ 1 × (2.5x) = 2.5x

∴ x + 2.5 = 2.5x

- Subtract x from both sides

∴ 2.5 = 1.5x

- Divide both sides by 1.5

∴ x = 5/3 ≅ 1.67

∵ x is the the time of his dad to wash the car alone

∴ Levi's dad takes 1.67 hours to wash the car by himself

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.

probably the last option

step-by-step explanation: