Which justifies Step 6 of his work?
![Which justifies Step 6 of his work class=](https://us-static.z-dn.net/files/d56/96c504fbb18d56e0f41c5f62abe79b8f.png)
Answer:
Identity property of multiplication.
Step-by-step explanation:
1 is the identity of multiplication.
1 x a = a for every real number a.
Hence, x = 20 is a real number, therefore
1 × x = x, identity property was used.