The minus, negative, or subtraction symbol is derived from a tilde written over "m" that used to be used to indicate subtraction. It might also be a shorthand version of the "m" itself.
Obviously it was not invented. It was always just there.
who invented subtraction?
the subtraction sign
The less than sign I believe that you are talking about is the minus/subtraction sign? The addition sign, +, is the opposite of the subtraction sign :)
A minus sign
A subtraction sign.
A subtraction sum will contain a minus sign.
It is called the minus sign. - .
Robert Recorde, who designed the equals sign, introduced plus and minus in 1557. Brahmagupta was an Indian mathematician who invented the multiplication sign around the 19th century. Johann Rahn first used the division sign in his book Teutshe algebra in 1659.