The correct answer is:
Jonathan uploaded 1 song.
Step-by-step explanation:
Let s be the number of songs Jonathan uploaded, and p be the number of pictures he uploaded.
Together he uploaded 11 items, which gives us
s+p=11.
Alissa uploaded 4 times as many songs, or 4s, and twice as many pictures, or 2p.
Together she uploaded 24 items, which gives us
4s+2p=24.
To solve this system of equations I will use substitution.
First, isolate a variable in our first equation, s+p=11.
We can isolate s by subtracting p from each side:
s+p-p=11-p;
s=11-p.
Now substitute this into the second equation:
4(11-p)+2p=24.
Use the distributive property:
4*11-4*p+2p=24;
44-4p+2p=24.
Combine like terms:
44-2p=24.
Subtract 44 from both sides:
44-2p-44=24-44;
-2p=-20.
Divide both sides by -2:
-2p/-2=-20/-2;
p=10.
Jonathan uploaded 10 pictures.
Using this in the first equation, s+10=11; subtract 10 from both sides:
s+10-10=11-10;
s=1.
Jonathan uploaded 1 song.