Final answer:
Patrick wrote the equivalent expression correctly: 15cb.
Step-by-step explanation:
Patrick wrote the equivalent expression correctly: 15cb.
To understand why, let's simplify Patty's expression first: (c + c + c) * (b + b + b + b + b) = 3c * 5b = 15cb.
So, Patrick's expression, 15cb, is equivalent to c35b, which matches the given expression c35b. Therefore, Patrick wrote the correct equivalent expression.