Question

A Web music store offers two versions of a popular song. The size of the standard version is 2.2

megabytes (MB). The size of the high-quality version is 4.6
MB. Yesterday, there were 1190
downloads of the song, for a total download size of 3386
MB. How many downloads of the standard version were there?

Answer 1

standard version is s
high quality version is h
2.2s - how many MB takes standard version
4.6h - how many MB takes high quality version

we got system of equations
s+h=1190
2.2s +4.6h =3386

h=1190-s substitute it into second equation
2.2s +4.6(1190-s) =3386
2.2s+4.6*1190 - 4.6s =3386
- 2.4s= 3386-4.6*1190
- 2.4s= 3386-5474
- 2.4s= -2088
s = 870