Answer:
Explanation:
If it is, the first and last terms are perfect squares, and the middle term is twice the product of the roots of those squares.
16x^ = (4x)^2 . . . . a perfect square
49 = 7^2 . . . . . . . a perfect square
-2(4x)(7) = -56x . . . . . matches the middle term, so the factoring is ...
16x^2 -56x +49 = (4x -7)^2
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The sign in the binomial factors is the same as the sign of the middle term of the trinomial.