Question

a magazine has 5580000 subscribers this year. This number is down 7% from last year. How many subscribers were there last year?

Answer 1

Let s=number of subscribers last year.

s(100-7)/100=5580000

93s/100=5580000  multiply both sides by 100

93s=558000000  divide both sides by 93

s=6000000  (that's 6 million subscribers last year)

Answer 2

$5580000=0.07\times\alpha$ being that $\alpha$ is the original value of subscribers the previous year.
To find, divide: $558000/0.07\approx79714285.71$ which rounds to $79714286$ subscribers.