Precalculus Examples

Find the GCF 28 and 42
28 and 42
Step 1
Find the common factors for the numerical part:
28,42
Step 2
The factors for 28 are 1,2,4,7,14,28.
Tap for more steps...
Step 2.1
The factors for 28 are all numbers between 1 and 28, which divide 28 evenly.
Check numbers between 1 and 28
Step 2.2
Find the factor pairs of 28 where xy=28.
xy12821447
Step 2.3
List the factors for 28.
1,2,4,7,14,28
1,2,4,7,14,28
Step 3
The factors for 42 are 1,2,3,6,7,14,21,42.
Tap for more steps...
Step 3.1
The factors for 42 are all numbers between 1 and 42, which divide 42 evenly.
Check numbers between 1 and 42
Step 3.2
Find the factor pairs of 42 where xy=42.
xy14222131467
Step 3.3
List the factors for 42.
1,2,3,6,7,14,21,42
1,2,3,6,7,14,21,42
Step 4
List all the factors for 28,42 to find the common factors.
28: 1,2,4,7,14,28
42: 1,2,3,6,7,14,21,42
Step 5
The common factors for 28,42 are 1,2,7,14.
1,2,7,14
Step 6
The GCF (HCF) of the numerical factors 1,2,7,14 is 14.
14
and 
(
(
)
)
|
|
[
[
]
]
7
7
8
8
9
9
°
°
θ
θ
4
4
5
5
6
6
/
/
^
^
×
×
>
>
π
π
1
1
2
2
3
3
-
-
+
+
÷
÷
<
<
,
,
0
0
.
.
%
%
=
=
 [x2  12  π  xdx ]