For the equation 7.5d = 2.5d, only Elena would find the solution.
In mathematics, when we need to solve an equation, means we need to find the values of the variables of that equation that fulfill the condition stated by the equation.
For given question, we have been given an equation 7.5d = 2.5d
We need to solve above equation means we need to find the value of d for which given equation is true.
Lin divides each side of given equation by 2.5d
⇒ 7.5d / 2.5d = 2.5d / 2.5 d
⇒ 3 = 1
which is not true.
This means, Lin is incorrect.
Now, Elena subtracts 2.5d from each side of equation.
⇒ 7.5d - 2.5d = 2.5d - 2.5d
⇒ (5.0)d = 0
⇒ d = 0 / 5
⇒ d = 0
For d = 0 the equation would be,
⇒ 7.5 × 0 = 2.5 × 0
⇒ 0 = 0
which is true.
This means, Elena is correct.
Therefore, while solving the equation 7.5d = 2.5d, only Elena would find the solution.
Learn more about an equation here:
https://brainly.com/question/13170101
#SPJ4