Answer:
Step-by-step explanation:
To find the difference (3c - d)² you should recognize that it is the square of a difference of two terms.
The square of the difference of two terms is a special case that you should remember: it is equal to the square of the first, minus twice the product of the first and second, plus the square of the second:
For the binomial (3c - d)² you have that:
Thus:
- (3c -d)² = (3c)² - 2(3c)(d) + d² = 9c² -6cd + d² ← answer