Division by negative numbers follow the same rule as multiplication. That is, (-ve and +ve) or (+ve and -ve) make -ve (-ve and -ve) or (+ve and +ve) make +ve. So the absolute value of 3/(-3) is 1 and the sign is (+ve and -ve) = -ve so that the answer is -1.

Marie Curie and Pierre Curie was Irene Curie's parents.

Pierre Curie

Eve Denise Curie Labouisee was a French-American author and writer.

Another Eve Curie was the daughter of Marie Curie.

Polonium was discovered by Marie Curie and Pierre Curie in 1898.