Question

20minus plus 8

Answer 1

20 - (8) = 12

Answer 2

or if you meant this: -20 + 8 = -12

Answer 3

20 -+ 8 = 12

Because when +- or -+ are together it becomes -
Otherwise ++ or -- become +

Answer 4

or maybe you meant
\[20\mp8\], i.e. \(20-8\), \(20+8\)
\(12\), \(28\)