Respuesta :

1. A~ 2r^2 + 15r-50

2. B~ k^2 - 4k+3
(2r - 5)(r+10)
=2r^2 +20r -5r - 50
=2r^2 +15r  - 50
answer:
2r^2 +15r  - 50 (first choice)

(k-3)(k-1)
=k^2 - 3k - k + 3
=k^2 - 4k +3

answer 
k^2 - 4k +3 (second choice)