adding and subtraction number using greatest common factors 940-420=? What is the GCF?
940 = 20 x 47 ---> 47 is prime
420 = 20 x 21
The GCF = 20
To add or subtract numbers using their greatest common factor (GCF), we need to find the GCF of the given numbers first.
Step 1: Find the prime factors of both numbers.
The prime factorization of 940 is 2^2 * 5 * 47.
The prime factorization of 420 is 2^2 * 3 * 5 * 7.
Step 2: Identify the common prime factors.
The common prime factors between 940 and 420 are 2^2 and 5.
Step 3: Determine the GCF.
The GCF is the product of the common prime factors. Therefore, the GCF of 940 and 420 is 2^2 * 5 = 20.
Step 4: Perform the subtraction using the GCF.
Now we can subtract the two numbers: 940 - 420 = 520.
So, the result of 940 - 420 using their GCF is 520, and their GCF is 20.