SOLUTION: Simplify using difference of squares: (u^2+v-w)(u^2-v+w)

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Question 409239: Simplify using difference of squares:
(u^2+v-w)(u^2-v+w)

Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
%28u%5E2%2Bv-w%29%28u%5E2-v%2Bw%29
The difference of squares pattern is:
%28a%2Bb%29%28a-b%29+=+a%5E2+-+b%5E2
To use this pattern on your expression, we need to be able to rewrite your expression (at least in our heads) as the sum of an "a" and a "b" times the difference of that "a" and "b". Once you realize that the "a" and "b" can be any Math expression, then you will become a more powerful user of patterns.

Here's how we can rewrite your expression:
%28u%5E2%2B%28v-w%29%29%28u%5E2-%28v-w%29%29
Take a moment to see how this expression is equal to your original expression. Note how the minus in front of the parentheses in the second factor make the "-w" inside the parentheses equal to the "+w" in your original expression.

Once written this way, it is not hard to see that we have matched the difference of squares pattern (the left side) with the "a" being u%5E2 and the "b" being (v-w). So we can use the pattern to multiply, knowing that the answer will be difference of the squares of the "a" and the "b":
%28u%5E2%29%5E2+-+%28v-w%29%5E2
Squaring u%5E2 is simple. To square (v-w) we can use another pattern: %28a-b%29%5E2+=+a%5E2+-2vw+%2B+w%5E2:
u%5E4+-+%28v%5E2+-2vw+%2B+w%5E2%29
Note the use of parentheses. That whole entire expression is %28v-w%29%5E2. And if we were subtracting %28v-w%29%5E2 before then we need to subtract the whole expression when we replace %28v-w%29%5E2.
One last simplification:
u%5E4+-+v%5E2+%2B+2vw+-+w%5E2%29

The alternative to using the pattern to multiply is to multiply the trinomials the "normal" way: Multiply each term of one polynomial by each term of the other and then add like terms,if any. This would mean 9 multiplications plus adding like terms. Using the patterns, once you learn how, makes this much easier.