Question 1066107
<pre><b>Substitute the vertex (x,y) = (11,-2) into each one

1. y=2x²-44x+120 
  -2=2(11)²-44(11)+120
  -2=2(121)-484+120
  -2=242-484+120
  -2=-122
False, so 1 is eliminated

2. y=2x²-44x-240
  -2=2(11)²-44(11)-240
  -2=2(121)-484-240
  -2=242-484-240
  -2=-482
False, so 2 is eliminated


3. y=2x²-44x+240
  -2=2(11)²-44(11)+240
  -2=2(121)-484+240
  -2=242-484+240
  -2=-2
True, so 3 is possible

4. y=-2x²-44x+240
  -2=-2(11)²-44(11)+240
  -2=-2(121)-484+240
  -2=-242-484+240
  -2=-486
False, so 4 is eliminated

So the only possibility is 3.

Lots of times, eliminating the incorrect choices is
easier than solving the problem.

Edwin</pre></b>