Question 1058560
If the number of R&B songs and the number of jazz songs are the same, then x = y.


Substituting y in place of x in the equation gives:


6x + 4x + 125 = 845


10x + 125 = 845


10x = 845 - 125


10x = 720


x = 72


Solution: Dad has 72 R&B songs and 72 jazz songs on his mp3 player. Combined, he has 144 R&B and jazz songs.