Answer:
1r
Step-by-step explanation:
(5r-4)(2r-6r+4)
1(5r-4)+1(2r-6r+4)
5r-4+2r-6r+4
5r+2r-6=1r
1r-4+4
-4+4=0
n+n+1+n+2=3n+3=3(n+1)
6
4 and 5 hope this helps