Answer:
The sum is a binomial of degree 3.
Explanation:
You are adding two binomials. Each binomial has two terms.
The terms 6s^2t and 4s^2t are like terms and combine to give the sum 10s^2t.
The terms -2st^2 and -3st^2 are like terms and combine to give the sum -5st^2.
The sum of the binomials is the binomial 10s^2t - 5st^2.
Since each original binomial is of degree 3, the sum is also of degree 3.
Answer: The sum is a binomial of degree 3.