There zeros of a function mean the x-intercepts. simpler way: At what x-values does the graph of the equation intersect the x-axis.
I don't know the if the last term of your function is +1 or -1 , so I did both for you using desmos graphing calculator.
You can also use quadratic formula, and do the algebra, and see if you get the same answer.
Linear- blue graph, table 2, 2x-3y=7, y=3\x +2, y=-4
Nonlinear- y= 2x^2+ 4