Question

Lin divides 2.5d from both sides on the equation 7.5d=2.5d. Elena subtracts 2.5d from each side of the equation. Who’s right?

Answer 1

Answer:

Elena's right

Step-by-step explanation:

Well, in the equation: 7.5d = 2.5d. Lin can divides 2.5d from both sides if the d≠0. If d=0, Lin cannot divides 2.5d from both sides.

So, Elena subtracts 2.5d from each side of equation is correct.

Lin method:

7.5d = 2.5d ⇔ $\frac{7.5}{2.5}$ = 1

Wrong equation.

Elena method:

7.5d = 2.5d ⇔ 5d = 0 ⇔ d=0

Conclusion: Elena's right