When you have two fractions being divided, you can flip the second one and then multiply straight across. So in this case the top of your final answer would be the numerator of the first fraction multiplied by the denominator of the second:
(3x - 6)(2x - 1) = 6x^2 - 15x + 6
Then the bottom of your answer would be the denominator of the first fraction multiplied by the numerator of the second one:
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.
