posted by Lucas .
Please, please could you be so nice and help me with step by step, I can't find right solution, Thank you so much!!!!
always set everything equal to zero. That way if you find factors, you knwo that each factor that is zero will provide a root.
-4r^2 + 20r - 13 = 0
use the quadratic formula to get
r = 5/2 ± √3
-2s^2 - 26s + 1 = 0
s = -1/2 (13 ± 3√19)