Assume that y varies directly with x, then solve.
If y=12 when x=15, find x when y=21.

The answer is in a fraction!
it is x = 105 / ? , I cant figure out the bottom .

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 

It would be 0 at least it should be