Answer:
[tex]a^2-ab[/tex]
Step-by-step explanation:
We need to find the sum of [tex]a^2-2ab+b^2[/tex] and [tex]2a^2+2ab+b^2[/tex] first.
Adding [tex]a^2-2ab+b^2[/tex] + [tex]2a^2+2ab+b^2[/tex]
Combining like terms, we get
[tex]a^2+2a^2=3a^2[/tex]
-2ab+2ab = 0
[tex]b^2+b^2=2b^2[/tex]
Therefore,
[tex]a^2-2ab+b^2 +2a^2+2ab+b^2=3a^2+2b^2[/tex].
Now, we need to find the sum of [tex]a^2-b^2 \ \ and \ \ a^2+ab+3b^2.[/tex].
Adding [tex]a^2−b^2+a^2+ab+3b^2[/tex].
Combining like terms, we get
[tex]a^2+a^2=2a^2[/tex]
[tex]-b^2+3b^2=2b^2[/tex].
Therefore,
[tex]a^2−b^2+a^2+ab+3b^2=2a^2+ab+2b^2.[/tex]
Now, subtracting
[tex]3a^2+2b^2 -(2a^2+ab+2b^2)[/tex].
Distributing minus sign over second parenthesis, we get
[tex]3a^2+2b^2-2a^2-ab-2b^2[/tex].
Combining like terms,
[tex]3a^2-2a^2=a^2[/tex]
[tex]2b^2-2b^2=0[/tex]
Therefore,
[tex]3a^2+2b^2-2a^2-ab-2b^2=a^2-ab[/tex].
Therefore, the difference of the sum of [tex]a^2-2ab+b^2[/tex] + [tex]2a^2+2ab+b^2[/tex] and [tex]a^2-b^2+a^2+ab+3b^2.[/tex] is [tex]a^2-ab.[/tex]