Respuesta :

irspow
find delta y/delta x

(10-7)/(15-12)=3/3=1,  (15-10)/(20-15)=5/5=1

y=x+b, using any point, I'll use (20,15) we can solve for b...

15=20+b

b=-5 so our line is:

y=x-5, and we want to know when y=17

17=x-5

x=22

so n=22