Respuesta :
21p + 10g = 770 ...multiply by -2
7p + 20g = 840
-------------------
-42p - 2g = - 1540 (result of multiplying by -2)
7p + 20g = 840
------------------
-35p = - 700
p = -700/-35
p = 20 <=== pink sponsorships cost $ 20 a piece
** the gold ones cost 35 per sponsor
7p + 20g = 840
-------------------
-42p - 2g = - 1540 (result of multiplying by -2)
7p + 20g = 840
------------------
-35p = - 700
p = -700/-35
p = 20 <=== pink sponsorships cost $ 20 a piece
** the gold ones cost 35 per sponsor