Determine Method: Determine the appropriate method to factor the expression 25r2−4. This expression is a difference of squares because it can be written as a2−b2, where a2 is a perfect square and b2 is a perfect square.
Identify Squares: Identify the terms in the expression 25r2−4 as squares.25r2 can be written as (5r)2 because 5r×5r=25r2.4 can be written as 22 because 2×2=4.So, 25r2−4 is in the form of a2−b2 where a=5r and 25r20.
Apply Formula: Apply the difference of squares formula to factor the expression.The difference of squares formula is a2−b2=(a−b)(a+b).Using a=5r and b=2, we get:(5r)2−22=(5r−2)(5r+2).
Write Factored Form: Write the final factored form of the expression.The factored form of 25r2−4 is (5r−2)(5r+2).
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