Your friend is correct in solving the equation $3x = 15$ using the Multiplication Property of Equality, but it's more commonly called the Division Property of Equality in this context. Let's break it down:

1. Multiplication Property of Equality states that if you multiply both sides of an equation by the same non-zero number, the equality is preserved. However, in this case, to isolate $x$, we divide both sides by 3 (the coefficient of $x$) rather than multiply.

2. The steps to solve $3x = 15$ are as follows:

   • Divide both sides of the equation by 3: $\frac{3x}{3} = \frac{15}{3}$
   • Simplifying this: $x = 5$

In this case, using Division Property of Equality is the appropriate method to isolate the variable $x$, not multiplication. So, while your friend may have the right approach in solving the equation, the terminology would technically be the Division Property of Equality.

Would you like a more detailed breakdown of this concept, or do you have any questions?

Here are 5 related questions to expand your understanding:

1. What is the Addition Property of Equality, and how does it differ from the Multiplication Property?
2. Can you use both properties in the same equation? If so, how would that look?
3. What would happen if you multiplied or divided by zero while solving an equation?
4. How would you solve the equation if it was $3x - 5 = 15$?
5. How do we check if our solution $x = 5$ is correct in this example?

Tip: When solving linear equations, always aim to isolate the variable by performing inverse operations (addition for subtraction, division for multiplication, etc.).