1720 - 1040 = 680
680/7 = 97.1
I would put them in intervals of 100
Your answer is A have a good day
It's the graphs that don't touch the x-axis have complex roots. Roots are the points where the parabola touches the x-axis. A,C and E all cross/touch the x-axis so they have real roots.
non-real or complex root parabolas are: B, D, F