Answer:
8,-10
Step-by-step explanation:
r²+2r=80
r²+2r-80=0
r²+(10-8)r-80=0
r²+10r-8r-80=0
r(r+10)-8(r+10)=0
(r-8)(r+10)=0
either, or,
r-8=0 r+10=0
r=8 r=-10
