Final answer:
To simplify the expression in parentheses, we use the distributive property, which allows multiplying each addend by the number outside the parentheses, followed by combining like terms by adding their coefficients.
Step-by-step explanation:
To simplify the expression in parentheses and then combine like terms, we first use the distributive property. The distributive property states that when you multiply a sum by a number, it's the same as multiplying each addend by that number and then adding the products. For example, A(B+C) can be expanded to AB + AC. This property allows you to simplify expressions with parentheses before combining like terms, which are terms that have the same variable raised to the same power. Once the parentheses are removed using the distributive property, like terms can be combined by adding or subtracting their coefficients.