Consider the equation<br> 2 5<br> x 2X-1<br> Solve for x.

Washing his dad's car alone, eight-year-old Levi takes 2.5 hours. If his dad helps him, then it takes 1 hour. How long does it t

Dmitry [639]

Answer:

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

∴ $\frac{1}{2.5}(1)+\frac{1}{x}(1)=1========\frac{1}{2.5}+\frac{1}{x}=1$

- Multiply both sides by 2.5x to cancel the denominators

∵ $\frac{1}{2.5}(2.5x)=x=====\frac{1}{x}(2.5x)=2.5$

∵ 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

3 0

3 years ago

Read 2 more answers

A ladder is leaning against a wall. The top of the ladder is 9 feet above the ground. If the bottom of the ladder is moved 3 ft

Alenkinab [10]

Let L represent the ladder length, and x the distance the horiz. ladder reaches out from the wall. Then L = x + 3, where x is the distance of the bottom of the ladder from the wall when the top of the ladder is 9 ft. above the ground.

Consider the triangle formed by the hypotenuse (L, same as ladder length), the (vertical) side opposite the angle formed by the hypo. (with length 9 ft) and the horiz side (which we will call x). Then, according to the Pythagorean Theorem,
L^2 = x^2 + 9^2. But L = x + 3, and L^2 = x^2 + 6x + 9 = x^2 + 9^2. Solving this equation results in x=3. 6x + 9 = 9^2, or
6x + 9 = 81
6x = 72
x = 12

But L = x+3. So L=12+3, or L = 15 (feet).

4 0

3 years ago

8(1/2u+3/4)

netineya [11]

Answer:

4u+3

Step-by-step explanation: 8/1*1/2= 8/2=4u

8/1*3/4= 24/8=3

4 0

2 years ago

Find f-1(x) if f(x)=2x+1

Mila [183]

Answer:

${f}^{ - 1} (x) = (2x + 1) ^{ - 1} \\ \\ {f}^{ - 1} (x) = \frac{1}{2x + 1}$

I hope I helped you^_^

3 0

3 years ago

3. Kurt's car gets 23 miles to a gallon of gasoline. He filled up his car's gas tank with g gallons. Write an expression that sh

ozzi

The expression D=23g shows the distance that Kurt can drive on a tank of gasoline.

Step-by-step explanation:

Given,

Distance covered by Kurt's car = 23 miles per gallon of gasoline

Kurt fills up tank of his car with g gallons.

Number of gallons in car's tank = g gallons

Distance covered by g gallons = D = Distance covered by one gallon * Number of gallons

D = 23*g

D = 23g

The expression D=23g shows the distance that Kurt can drive on a tank of gasoline.

Keywords: distance, multiplication

Learn more about multiplication at:

#LearnwithBrainly

3 0

3 years ago

Consider the equation 2 5 x 2X-1 Solve for x.