Question

Reduce $\frac{-45}{30}$ to standard form

Answer 1

A rational number is said to be in the standard form if its denominator is a positive integer and the numerator and denominator have no common factor other than 1.

$\frac{-45}{30}=\frac{-45÷3}{30÷3}$

$=\frac{-15}{10}$

$=\frac{-15÷5}{10÷5}$

$=\frac{-3}{2}$

We had to divide twice. First time by 3 and then by 5. This could also be done as

$\frac{-45}{30}=\frac{-45÷15}{30÷15}$

$=\frac{-3}{2}$

In this, note that 15 is the HCF of 45 and 30