Answer:
82
Step-by-step explanation:

1957 avg rate of 500,000 per every person
Answer:1600
Step-by-step explanation:
75/1200=100/x
75x=120000
/75
×=1600
5x-8y=1...(1)
3x+6y=-21...(2)
(1)*3:
15x-24y=3...(3)
(2)*5:
15x+30y=-105...(2)
(3)-(2):
15x-24y-(15x+30y)=3-(-105)
15x-24y-15x-30y=108
-54y=108
y=-2