+2448 
I'm actually really sick right now which is why I've been asking for help because I need to get a lot of math work completed because I have a TON of assignments that need to be done and I haven't really learned the material yet. >.<
+128406 16).....I think this is correct...
16/20 = ? / 45
4/ 5 = ? /45 cross-multiply
45*4 = 5*?
180 = 5*? divide by 5
36 = ?
17)
?/10 = 20/25
?/10 = 4/5 cross-multiply
5? = 4 * 10
5? = 40 divide both sides by 5
? = 8
18)
?/4 = 6/3
?/4 = 2 multiply both sides by 2
? = 8
19)
12/9 = ? / (33-9)
4/3 = ? / 24 cross-multiply
24*4 = 3* ?
96 = 3 * ? divide both sides by 3
32 = ?
