3y = 5x + 30
y + 5x = 50 .......(1)
3y - 5x = 30 .....(2) - rearranging the first equation.
Add (1) and (2):-
4y = 80
y = 20
Now plug y = 20 into equation (1):-
20 + 5x = 50
5x = 30
x = 6
The 2 numbers are 6 and 20.
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
C ⠀ ⠀ ⠀ ⠀ ⠀
The points between 0 and 1 increase in increments of 1/6th