Carlota’s smartphone contains 500 megabytes of data. She uses 300 megabytes for applications and the rest for music. If each song takes an average of 4 megabytes, which equations can be used to find the number of songs on Carlota’s smartphone? Select all that apply. A. 500−300=4n B. 500+300=4n C. 4n+300=500 D. 300−4n=500