Precalculus Examples
5b-15abc5b−15abc
Step 1
Since 5b,-15abc5b,−15abc contains both numbers and variables, there are two steps to find the GCF (HCF). Find GCF for the numeric part, then find GCF for the variable part.
Steps to find the GCF for 5b,-15abc5b,−15abc:
1. Find the GCF for the numerical part 5,-155,−15
2. Find the GCF for the variable part b1,a1,b1,c1b1,a1,b1,c1
3. Multiply the values together
Step 2
Find the common factors for the numerical part:
5,-155,−15
Step 3
Step 3.1
The factors for 55 are all numbers between 11 and 55, which divide 55 evenly.
Check numbers between 11 and 55
Step 3.2
Find the factor pairs of 55 where x⋅y=5x⋅y=5.
xy15xy15
Step 3.3
List the factors for 55.
1,51,5
1,51,5
Step 4
Step 4.1
The factors for -15−15 are all numbers between 11 and 1515, which divide -15−15 evenly.
Check numbers between 11 and 1515
Step 4.2
Find the factor pairs of -15−15 where x⋅y=-15x⋅y=−15.
xy11535xy11535
Step 4.3
List the factors for -15−15.
1,3,5,151,3,5,15
1,3,5,151,3,5,15
Step 5
List all the factors for 5,-155,−15 to find the common factors.
55: 1,51,5
-15−15: 1,3,5,151,3,5,15
Step 6
The common factors for 5,-155,−15 are 1,51,5.
1,51,5
Step 7
The GCF for the numerical part is 55.
GCFNumerical=5GCFNumerical=5
Step 8
Next, find the common factors for the variable part:
b,a,b,c
Step 9
The factor for b1b1 is bb itself.
bb
Step 10
The factor for a1a1 is aa itself.
aa
Step 11
The factor for b1b1 is bb itself.
bb
Step 12
The factor for c1c1 is cc itself.
cc
Step 13
List all the factors for b1,a1,b1,c1b1,a1,b1,c1 to find the common factors.
b1=bb1=b
a1=aa1=a
b1=bb1=b
c1=cc1=c
Step 14
The common factor for the variables b1,a1,b1,c1b1,a1,b1,c1 is bb.
bb
Step 15
The GCF for the variable part is bb.
GCFVariable=bGCFVariable=b
Step 16
Multiply the GCF of the numerical part 55 and the GCF of the variable part bb.
5b5b