Dora joined a new school.
She has to walk
$32 $
$km$
from home to reach school.
Soon after school, Dora has to go to tuition.
She walks back
$31 $
$km$
in the direction of home to reach tuition.
How far is Home from Tuition?
To find distance between tuition and home, we subtract the two distances.
Here, we are subtracting two rational numbers.
Let us learn about subtraction of two rational numbers.
If the rational numbers in the subtraction have same denominator.
Retain the denominator.
And find the difference between the numerators.
Subtracting a rational number is same as adding its additive inverse.
Let us solve few examples.
Find the difference of given rational numbers.
Subtracting
$54 $
is same as adding additive inverse of
$54 $
Find the difference of given rational numbers.
Adding the additive inverse of
$72 $
As the denominators are not equal, take LCM of denominators.
Further simplifying we get the difference as,
Find the difference of
$−73 $
and
$92 $
Adding additive inverse of
$−73 $
to
$92 $
.
Since denominators are not equal, solve further by taking LCM.
Revision
Steps to subtract two rational numbers.
Step 1 : Check if the denominators are equal.
Step 2 : If the denominators are equal, retain denominator,
And write difference of numerators in the numerator.
If the denominators are not equal, make them equal by taking LCM.
Subtracting a rational number is same as adding its additive inverse.
The end