Which of the following statements is incorrect?

Let us check each option one by one.

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The terms 2x²y and 4xy² have the same variables but have different powers. So, 2x²y and 4xy² are Unlike terms.

Therefore, the given statement is incorrect.

**

The given expression is 5p²q + 7pq² + 12pq + 36.

Terms in the given expression = 5p²q, 7pq², 12pq, 36

Since the given expression contains 4 terms, it is a correct statement.

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3xy = 3 × x × y

3, x, and y are the factors of 3xy.

Therefore, the given statement is correct.

**

The coefficient of y² in the expression −3x²y + 7xy² + 31 is 7x.

Therefore, the given statement is correct.