How would you write a real-world problem that models the following equation: −x+40=x?(1 point)

Responses

The amount of money a stock lost in the stock market was $40 more than it gained.
The amount of money a stock lost in the stock market was $40 more than it gained.

Marsha is below sea level. To get as far above sea level as she is below, she would have to move to a location 40 feet higher.
Marsha is below sea level. To get as far above sea level as she is below, she would have to move to a location 40 feet higher.

The number of days that the temperature has been below zero is 40 fewer than the number of days the temperature has been above zero.
The number of days that the temperature has been below zero is 40 fewer than the number of days the temperature has been above zero.

If Alex gained as much money as she lost, she would have 40 dollars.

1 answer

To model the equation \(-x + 40 = x\), we want to create a real-world problem that represents the relationship described by the equation.

The equation essentially states that a certain loss, represented by \(-x\), combined with 40 results in the same value as a certain gain, represented by \(x\).

Let's break down the options provided:

  1. The amount of money a stock lost in the stock market was $40 more than it gained.

    • This statement can be represented as \( -x = x + 40\), which is not the same as our equation.
  2. Marsha is below sea level. To get as far above sea level as she is below, she would have to move to a location 40 feet higher.

    • This could represent a balance of her current position below sea level and the additional height needed, but it more closely fits a different model.
  3. The number of days that the temperature has been below zero is 40 fewer than the number of days the temperature has been above zero.

    • This can be represented as \( -x = x - 40\). This model does not fit our equation either.
  4. If Alex gained as much money as she lost, she would have 40 dollars.

    • This can be expressed as \( -x + 40 = x\), which correctly models the concept of having $40 additional after losses equal to gains.

Based on the analysis, the best real-world problem that models the equation \(-x + 40 = x\) is:

If Alex gained as much money as she lost, she would have 40 dollars.