REGRA DOS SINAIS - Diferenças da Adição e Subtração para a Multiplicação e Divisão

🔗 Buy the ENEM Math 800+ course: https://pay.hotmart.com/C97770743H Get to know our platform at http://www.matematicario.com.br Understand the differences between the rules for addition and subtraction signs and the rules for multiplication and division. Come with me! Post link: https://goo.gl/JCcqhK Matemática Rio is a channel with free and creative online math classes! Learn interesting content in just a few minutes! Created by Professor Rafael Procopio: Post-graduation in Mathematics Teaching (UFRJ); Mathematics teacher in the public school system of Rio de Janeiro. Mathematics Rio on social media: Facebook:   / matematicario   Twitter:   / matematicario   Google+: http://www.google.com/+MatematicaRio