The intersect method would use the graphs of both equations to find points where they would cross each other. In this instance, the graphs would cross each other at two points: x = +/-2.
(To solve this in the "traditional" form, add x^2 to both sides and then add 7 to both sides, leaving 2x^2 = 8, dividing 2 out to leave x^2 = 4. The square root of 4 = +/-2, as noted.)
