No, 28 is not a common factor of 7 and 2. Factors of a number are integers that can be multiplied together to get that number. In this case, the factors of 7 are 1 and 7, and the factors of 2 are 1 and 2. Since 28 is not a factor of either 7 or 2, it is not a common factor of the two numbers.
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Oh honey, bless your heart for asking. Let me break it down for you - 28 is not a common factor of 7 and 2. In fact, the only factors of 7 are 1 and 7, and the only factors of 2 are 1 and 2. So, 28 can't sit with them at the cool kids' table of factors.
CAREFUL! 28 is a common multiple of 7 and 2!
The common factors of 7 are:
1 x 7
-1 x -7
The common factors of 2 are:
1 x 2
-1 x -2
So, as you can see, the common factors of 7 and 2 are 1and -1
196 = 2 x 2 x 7 x 7; 420 = 2 x 2 x 3 x 5 x 7. Common factors 2 x 2 x 7 ie 28 is the HCF.
To find the greatest common factor (GCF), first find the prime factorization of the two numbers. The GCF is the product of all of the prime factors the two numbers have in common. Prime factors of 28: 2, 2, 7 Prime factors of 68: 2, 2, 17 They have in common: 2, 2. 2x2=4 The GCF is 4.
28:8 :: 7:2 ;; 3.5:1 NB note the use of colons, instead of writing out 'ratio to' all the time.
The factors of 28 are:1, 2, 4, 7, 14, 28The factors of 42 are:1, 2, 3, 6, 7, 14, 21, 42The factors of 70 are:1, 2, 5, 7, 10, 14, 35, 70The common factors are:1, 2, 7, 14The Greatest Common Factor (GCF) is: 14
7(x - 2)(x + 2)