Answer:
Distributive property
Step-by-step explanation:
The question is not properly formatted.
From the available detail, I will re-write the question as follows
[tex]45x + 3(25x + 75y)[/tex]
Required
The property used
Distributive property is stated as follows:
[tex]a(b \± c) = ab \± ac[/tex]
So, we have:
[tex]45x + 3(25x + 75y) = 45x + 75x + 225y[/tex]
Evaluate like terms
[tex]45x + 3(25x + 75y) = 120x + 225y[/tex]