8/15 = 56/105
This may be solved using proportion.
a/b = c/d
ad = bc where cross products are equal.
a = 8
b = f
c = 56
d = 105
ad = bc
8*105 = f*56
840 = 56f
840/56 = 56f/56
f = 15
56 ÷ 7 = 8
105 ÷ 7 = 15
To expand two terms such as these, we can use the method called FOIL (stands for First, Outer, Inner, Last). Here is what I mean:
We have two terms: (x - 2)(x - 1)
We should first multiply the First two terms of each term in order to complete the F stage:
(x)*(x) =

So then, we take the two outer terms and multiply them together to complete the O stage:
(x)*(-1) = -x
So far we have two things that we have calculated; at the end of the FOIL process we will have four.
To keep going with the FOIL, we now multiply the two inner terms to complete the I stage:
(-2)*(x) = -2x
Last but not least, we need to complete the L stage - so we multiply the two last terms of each term:
(-2)*(-1) = 2
Now that we have our four terms, let us add them together and combine like terms:

Since -x and -2x both have the x portion in common and they are added together, we can add them to create one single term:
-x + (-2x) = -3x
So now that we have our terms completed, we can combine into one polynomial equation:

or
Answer:
5/the number of socks he has
Answer:
9r
Step-by-step explanation:
1.5r - 3r + 10.5r
10.5r + 1.5r = 12r
12r - 3r = 9r
Final Answer = 9r