Negative numbers

This rule shows that subtracting a negative number $-b$ is equivalent to adding the positive number $b$. Reverse the sign of the subtracted number and perform addition.

This formula shows that multiplying two negative numbers yields a positive product. The product of two numbers with the same negative sign is always positive.

This formula shows that multiplying a negative number by a positive number yields a negative product. The product of numbers with opposite signs is always negative.

This rule shows that dividing two negative numbers yields a positive quotient. Dividing numbers with matching negative signs results in the positive fraction $\frac{a}{b}$.