Answer:
The identity property of multiplication
Explanation:
If a, b and c are any real numbers,
By addition property of equality,
a = b ⇒ a + c = b + c,
By identity property of addition,
a + 0 = a,
By multiplication property of equality,
a = b ⇒ a × c = b × c,
By identity property of multiplication,
a × 1 = a
Thus, it is clear that,
'The identity property of multiplication' justifies Step 6 .