18). 16:80 is the ratio but in simplest form is; 5:0
19). 36:54 is the ratio but in simplest form is; 2:3
20). 12:24 is the ratio but in simplest form is; 1:2
hope that helps:D
(x-1) (x + 10)
Step-by-step explanation:
I think it's this but I'm not sure if I did it right