Sanjay solved the equation below. Which property did he use to determine that [tex]7x + 42 = 42[/tex] is equivalent to [tex]7x = 0[/tex]?

[tex]\[
\begin{aligned}
7(x+6) & = 42 \\
7x + 42 & = 42 \\
7x & = 0 \\
x & = 0
\end{aligned}
\][/tex]

A. distributive property of equality
B. subtraction property of equality
C. multiplication property of equality
D. division property of equality



Answer :

To determine which property Sanjay used to show that [tex]\(7x + 42 = 42\)[/tex] is equivalent to [tex]\(7x = 0\)[/tex], let's carefully look at the steps he followed:

1. The equation begins with [tex]\(7(x + 6) = 42\)[/tex].
2. Expanding the left side using the distributive property gives [tex]\(7x + 42 = 42\)[/tex].
3. Sanjay then isolates the term involving [tex]\(x\)[/tex] by eliminating the constant on the left side. He does this by subtracting 42 from both sides of the equation:
[tex]\[ 7x + 42 - 42 = 42 - 42 \][/tex]
4. Simplifying this, we get:
[tex]\[ 7x = 0 \][/tex]

The property used in step 3, where Sanjay subtracts 42 from both sides to isolate [tex]\(7x\)[/tex], is called:

Subtraction property of equality.

Hence, Sanjay used the subtraction property of equality to determine that [tex]\(7x + 42 = 42\)[/tex] is equivalent to [tex]\(7x = 0\)[/tex].