Expand and simplify (2x + 7)(2x - 7).
Answer and explanation
Correct answer: D.
- Step 1: This is a difference of two squares: (a + b)(a - b) = a squared - b squared.
- Step 2: Here a = 2x and b = 7, so the result is .
Answer
.
Why not the others: : the middle terms cancel and the last term keeps its minus sign. : the middle terms were not cancelled. : the coefficients were not squared.
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