The first sign of syphilis is a small sore, called a chancre (SHANG-kur). The sore appears at the spot where the bacteria entered your body. While most people infected with syphilis develop only one chancre, some people develop several of them. The chancre usually develops about three weeks after exposure.
The colon is the symbol :. It is used in a number of different ways in mathematics. 1. To denote ratio or odds, as in 2:1 (voiced two to one). 2. To mean such that in constructions such as (voiced the set of numbers such that ). 3. To give a name to a map, e.g., (which is equivalent to the function notation ).
Two key features of algebra as we understand the word today are: 1. Reasoning about numbers by recognizing patterns across numbers; 2. Solving a problem by introducing a term for an unknown and then, starting with what is known, reasoning to determine its value. We first see the emergence of both features of algebra in the mathematics of ancient Babylonia, around 2,000 BCE. Several hundred of the many thousands of Babylonianâs cuneiform-inscribed clay tablets that have been found are devoted to mathematics.