greatest common factor of 45, 75, and 105.?
回答 (8)
2008-02-04 3:21 pm
✔ 最佳答案
1545 = 3*3*5 = 3*15
75 = 3*5*5 = 5*15
105 = 3*5*7 = 7*15
GCF is thus 15.
2008-02-04 3:26 pm
To determine the greatest common factor:
Factors each number into primes
45 = 3×3×5
75 = 3×5×5
105 = 3×5×7
Find the factors common to all three numbers: 3 and 5
Multiply the common factors: 3×5 = 15
GCF(45,75,105) = 15
Factors each number into primes
45 = 3×3×5
75 = 3×5×5
105 = 3×5×7
Find the factors common to all three numbers: 3 and 5
Multiply the common factors: 3×5 = 15
GCF(45,75,105) = 15
2008-02-04 3:23 pm
15...ah man someone already answered
2008-02-04 3:41 pm
45 = 3 x 3 x 5
75 = 3 x 5 x 5
105 = 3 x 5 x 7
--------------------
The GCF of 45,75,105 is:
3 x 5
= 15
75 = 3 x 5 x 5
105 = 3 x 5 x 7
--------------------
The GCF of 45,75,105 is:
3 x 5
= 15
2008-02-04 3:31 pm
This is my way to solve the problem:
Greatest common factor of 45, 75 and 105 =
..3.. / 45 | 75 | 105
..5.. / 15 | 25 | 35
/ 3 | 5 | 7
Greatest common factor = 3 x 5 = 15
Greatest common factor of 45, 75 and 105 =
..3.. / 45 | 75 | 105
..5.. / 15 | 25 | 35
/ 3 | 5 | 7
Greatest common factor = 3 x 5 = 15
2008-02-04 3:30 pm
By greatest common factor, do you mean highest common factor? If yes, then..
There're 2 ways to solve this (actually there're 3 but..let's leave the other one aside):
1) Algorithm (continuous division by Common Factor)
..5.. [] 45 ,75 ,105 = 45,75,105 are all divisible by 5.
..3.. [] 9 ,15 ,21 = 9,15,21 are all divisible by 3.
______3 ,5 ,7 = The division stop because 3,5,7 do not have any more common factors except for 1.
The answer will be: 5 x 3= 15.
2) Listing all the factors for each value
45 = 3×3×5 (Factors for 45)
75 = 3×5×5 (Factors of 75)
105 = 3×5×7 (Factors of 105)
HCF/ GCF = The factors that are present in ALL three value (5 and 3) and multiply them together..
So, the HCF/GCF is 5x3=15
There're 2 ways to solve this (actually there're 3 but..let's leave the other one aside):
1) Algorithm (continuous division by Common Factor)
..5.. [] 45 ,75 ,105 = 45,75,105 are all divisible by 5.
..3.. [] 9 ,15 ,21 = 9,15,21 are all divisible by 3.
______3 ,5 ,7 = The division stop because 3,5,7 do not have any more common factors except for 1.
The answer will be: 5 x 3= 15.
2) Listing all the factors for each value
45 = 3×3×5 (Factors for 45)
75 = 3×5×5 (Factors of 75)
105 = 3×5×7 (Factors of 105)
HCF/ GCF = The factors that are present in ALL three value (5 and 3) and multiply them together..
So, the HCF/GCF is 5x3=15
2008-02-04 3:26 pm
To get the GCF, factor each number into its primes:
45 = 3 X 3 X 5
75 = 5 X 5 X 3
105 = 5 X 3 X 7
Now take only those primes that are common to all 3 numbers, and multiply them together:
3 X 5 = 15
GCF = 15
45 = 3 X 3 X 5
75 = 5 X 5 X 3
105 = 5 X 3 X 7
Now take only those primes that are common to all 3 numbers, and multiply them together:
3 X 5 = 15
GCF = 15
2008-02-04 3:26 pm
15?
2008-02-04 3:24 pm
15 is the greatest number that divides all of them.
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