Someone please help?! Which of the following is a complex number?

-4+ square root 7/3

4/ square root 3 - 7 square root 3/5

5/2 - square root 15

2/3 + square root - 27/28

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Fuch th ckbj gcg ft tc jvuvuvu

Idon't see any graph, however the graph of the function : f(x) = x²-2x+3 is a parabola: 1) open upward (since a> 0)2) it intersects y-axis in 3 (y=3)3) its axis of symmetry is x = +1 ( -b/2a)4) it's minimum is y = -2, so its vertex is (1,-2)5) it doesn't intersect the x-axis since discriminant < 0