Answer
True for multiplication and division. Sometimes true for subtraction. Not true for addition.
A more precise statement would be:
"The multiplication or division of two negative numbers gives a positive result."
Work Step by Step
The statement, "Two negatives give a positive" is true for multiplication and division:
$(-x)*(-y)=+xy$
$\displaystyle \frac{-x}{-y}=+\frac{x}{y}$
However, the statement is not true for addition and only sometimes true for subtraction:
$(-x)+(-y)=-(x+y)$
$(-x)-(-y)=-x+y=y-x$ (positive if $y\gt x$, but negative if $y\lt x$)
A more precise statement would be:
"The multiplication or division of two negative numbers gives a positive result."
