-90
get a piece of paper and a pencil and figure it out!
6 of them plus 10 = 100
5f + 60 = 90 90 - 60 = 30 5 * ? = 30 5 * 6 = 30 (5)6 + 60 = 90
90 + 90 + 60 = 240
390
It is 90+90 = 180
90 minus 75 =15 therefore 15 + 75 = 90
54 + 560 + 90 = 704
42
6 + 2 + 90 = 98
190