Question

What is The property wrt multiplication used in -4/9×1=1×-4/9=-4/9

Answer 1

1 is the multiplicative identity, 
which means,
R*1=1*R=R
where R is any rational number

Answer 2

✴Hi,

➡Multiplicative Identity for rational numbers = 1

➡In the multiplication '-4/9 × 1 = 1 × -4/9 = -4/9', It shows us the property of EXISTENCE OF MULTIPLICATIVE IDENTITY OF RATIONAL NUMBERS.

➡When multiplicative identity is multiplied with any rational number, i.e. when any rational number is multiplied with 1, the rational number always remains the same. This property of rational numbers is called EXISTENCE OF MULTIPLICATIVE IDENTITY OF RATIONAL NUMBERS.

➡Let us take another example:
5/7 × 1 = 1 × 5/7 = 5/7.


✴Hope it helps.