Word problem maybe solved by quadratic equation.

In summary, the problem asks to find the time it takes for Eljen to paint a room alone, given that Eljen and Genelle can paint the room together in 4 hours and Genelle takes 2 hours less than Eljen when working alone. It can be solved using the equation \frac 1 a + \frac 1 b = \frac 1 t, where a and b represent the time it takes for each person to paint the room alone and t represents the time it takes for them to paint the room together.
  • #1
genelle
2
0

Homework Statement


Here the the word problem:
Genelle and Eljen can paint a room together in 4 hours. Working alone, Genelle can paint the room in two hours less than Eljen can. Find how long it takes Eljen to paint the room alone.

Homework Equations


Maybe, this problem can be solved using the quadratic equation.

The Attempt at a Solution


Please.. it's about quadratic erquation.
 
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  • #2
A general approach in these is to think about the RATES of work. If you have two people, say A and B, who require a hours and b hours when working alone to finish a job, and t hours when working together, the numbers a, b, and t are connected with this equation:

[tex]
\frac 1 a + \frac 1 b = \frac 1 t
[/tex]

Use the information provided in your question to set up the unknowns, and then the appropriate equation.
 
  • #3


I would approach this problem by first defining the variables involved. Let's say G represents the time it takes for Genelle to paint the room alone, and E represents the time it takes for Eljen to paint the room alone. We know that together, they can paint the room in 4 hours, so we can create the equation G + E = 4. We also know that Genelle can paint the room in 2 hours less than Eljen, so we can create the equation G = E - 2.

To solve for E, we can substitute G = E - 2 into the first equation, giving us (E - 2) + E = 4. Simplifying, we get 2E = 6, and therefore E = 3. This means it takes Eljen 3 hours to paint the room alone.

However, to confirm our answer, we can also use the quadratic equation, which is commonly used to solve for unknowns in equations with two variables. In this case, the equation would be G + E = 4, or E^2 - 4E + 4 = 0. Solving for E using the quadratic formula, we get E = (4 ± √12)/2, which simplifies to E = 2 ± √3. Since we know that E cannot be negative in this context, we can disregard the negative solution and confirm that E = 3, which is the same answer we obtained earlier.

In conclusion, yes, this word problem can be solved using the quadratic equation, but it is not the only method. As scientists, it is important for us to use critical thinking and choose the most appropriate method for each problem.
 

FAQ: Word problem maybe solved by quadratic equation.

What is a quadratic equation?

A quadratic equation is an algebraic equation in the form of ax^2 + bx + c = 0, where a, b, and c are constants and x is a variable.

How is a quadratic equation solved?

A quadratic equation can be solved by using the quadratic formula: x = (-b ± √(b^2 - 4ac)) / 2a, where ± indicates that there are two solutions.

What types of word problems can be solved by using quadratic equations?

Word problems that involve finding the maximum or minimum value, finding the dimensions of a rectangle with a given area, or finding the height or distance of an object in motion can be solved by using quadratic equations.

What are some real-life applications of quadratic equations?

Quadratic equations are commonly used in physics, engineering, economics, and other sciences to model and solve real-world problems. They can be used to predict the path of a projectile, determine the optimal production level for a company, or calculate the trajectory of a satellite.

Can a quadratic equation have more than two solutions?

No, a quadratic equation can have a maximum of two solutions, as indicated by the ± symbol in the quadratic formula. However, there may be cases where one or both of the solutions are repeated, resulting in fewer distinct solutions.

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