The Greatest Common Factor also known as GCF is the largest number that can divide equally into two or more numbers.
For the problem they ask 'Which number pair has a 'GCF' of 6.
First let's look at the answer choice 'A' that gives us 18 and 54.
Now for this we need to list the factors of both 18 and 54. A factor being a number that can be multiplied by another number to get the sum.
18: 1, 2, 3, 6, 9, 18
54: 1, 2, 3, 6, 9, 18, 27, 54
So right away we can see the the largest number that can be divided into both of them equally is not 6, it is 18. This means we can mark out A as a possible answer.
Next let's try B and list the factors of both 30 and 42.
30: 1, 2, 3, 5, 6, 15, 30
42: 1, 2, 3, 6, 7, 14, 21, 42
Looks like we found our answer! The largest factor they have in common is 6!
I'm still going to go ahead and list the GCF's for answers C and D.
1. Yes it does. It's a function because it pass in the vertical line test, which tell us that if you can draw an vertical line through the graph and this line touches the graph in only one point, it is a function.
The answer is letter c. x2-8x+24-[72/(x+3)]. If you do not know how to solve this using the long division method, you can always evaluate the options through the process of elimination first. Since the degree of the other factor is already 1 (x to the power of 1), you know that option d. is not the correct answer because you know that the other factor must be raised to the power of 2. That leaves us with a, b and c. Working backwards and multiplying the given factor (x+3) with the factor in b, gives us x3-5x2+72. So from there, you know that you have to eliminate 72, which can be removed when it is subtracted by itself. Letter c does just that. Try multiplying (x+3) and option c for yourself :).
