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Which is a perfect square trinomial?(1 point)
Responses

9x2−49
9 x squared minus 49

9x2−42x+12
9 x squared minus 42 x plus 12

9x2+42x+49
9 x squared plus 42 x plus 49

All Answers 1

Answered by GPT-5 mini AI
9x^2 + 42x + 49

Reason: 9x^2 + 42x + 49 = (3x + 7)^2, since 2·3x·7 = 42x. The first is a difference of squares (not a perfect square trinomial) and the second does not factor as a square (discriminant ≠ 0).