(a) find the gcf of 45 and 18
Gcf = ?
(b) use the gcf to factor 45+18
45+18=?x(?+?)
(a) The greatest common factor (GCF) of 45 and 18 is calculated by finding the largest integer that divides both numbers without leaving a remainder.
Let's list the factors of each:
45: 1, 3, 5, 9, 15, 45
18: 1, 2, 3, 6, 9, 18
From the lists above, the common factors of 45 and 18 are 1, 3, and 9. The greatest of these is 9.
So, GCF = 9
(b) To use the GCF to factor the expression 45 + 18, we first add the two numbers together and then factor the result using the GCF.
45 + 18 = 63
Now we factor 63 using the GCF, which is 9:
63 = 9 x 7
So, 45 + 18 factored by the GCF is:
45 + 18 = 9 x (45/9 + 18/9) = 9 x (5 + 2) = 9 x (7)
In the format you provided, it would look like this:
45 + 18 = 9 x (5 + 2)