Question

Verify Closure property for subtraction of $\frac{-4}{5}$ and $\frac{1}{2}$. (4 marks)

Answer 1

Here the two rational numbers are $\frac{-4}{5}$and$\frac{1}{2}$
Let's verify they are closed under subtraction or not.
= $\frac{-4}{5}$ - $\frac{1}{2}$=-4×2-1×52×5=-8-510
= $\frac{-13}{10}$
Here $\frac{-13}{10}$ is in the form $\frac{p}{q}$, where p and q are integers and q not equal to 0

(1.5 mark)

Now, lets reverse the order and check
$\frac{1}{2}$ - $\frac{-4}{5}$ = 1×5--4×22×5=5+810
= $\frac{13}{10}$
Here $\frac{13}{10}$ is in the form p/q, where p and q are integers and q not equal to 0

(1.5 mark)

Hence the two rational numbers $\frac{-4}{5}$ and $\frac{1}{2}$ are verified under closure property of subtraction.

(1 mark)