SOLUTION: A Web music store offers two versions of a popular song. The size of the standard version is 2.5 megabytes (MB). The size of the high-quality version is 4.2 MB. Yesterday, the hi

Algebra ->  Linear-equations -> SOLUTION: A Web music store offers two versions of a popular song. The size of the standard version is 2.5 megabytes (MB). The size of the high-quality version is 4.2 MB. Yesterday, the hi      Log On


   

Question 1149065: A Web music store offers two versions of a popular song. The size of the standard version is 2.5 megabytes (MB). The size of the high-quality version is 4.2 MB. Yesterday, the high-quality version was downloaded twice as often as the standard version. The total size downloaded for the two versions was 2398 MB. How many downloads of the standard version were there?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = number of downloads of the standard version
Let +b+ = number of downloads of the high-quality version
------------------------------
(1) +b+=+2a+
(2) +2.5a+%2B+4.2b+=+2398+
------------------------------
(2) +2.5a+%2B+4.2%2A%282a%29+=+2398+ MB
(2) +%28+2.5+%2B+4.2%2A2+%29%2Aa+=+2398+ MB
(2) +10.9a+=+2398+ MB
(2) +a+=+220+
and
(1) +b+=+2%2A220+
(1) +b+=+440+
There were 220 downloads of the standard version
-------------------------------
check:
(2) +2.5a+%2B+4.2b+=+2398+
(2) +2.5%2A220+%2B+4.2%2A440+=+2398+
(2) +550+%2B+1848+=+2398+
(2) +2398+=+2398+
OK