Answer:In a question like this, you are trying to find the Highest Common Denominator, or HCF. This can be done manually, by finding all the factors of 42
(
1
,
2
,
3
,
6
,
7
,
14
,
21
,
42
)
, all the factors of 72
(
1
,
2
,
3
,
4
,
6
,
8
,
9
,
12
,
18
,
24
,
36
,
72
)
, and comparing them to see that their HCF is
6
. Or, it can be done by dividing both numbers,
=
72
42
, simplifying the fraction
=
12
7
, then dividing the starting number with the new simplifiied number, remembering always to divide numerator with numerator and denominator with denominator.
72
12
=
6
or
42
7
=
6
This process works with any two numbers which you want to find the HCF of, and can be simplified into this rule:
If
a
=
any number,
b
=
any number and
c
d
is the simplified fraction of
a
b
,
The HCF
=
a
c
or
=
b
d
I hope that helped!
Step-by-step explanation:
