Now look at the graph to find another zero, a second copy of one of the zeroes you've already found. (Hint: Where the graph just touches the x-axis, instead of crossing it, the zero at that spot occurs twice... or four times, or six times, or some other even number of times. So any time the calculator graph shows the line reaching the axis and then turning around, check for a repeated zero.)
Note: Once you've removed three of the zeroes, you'll be left with a quadratic, to which you can apply the Quadratic Formula. (I'd factor the "2" out first, though.)
Eliz.