Question 1198895
<br>
{{{((x+2-a))^2+((2-a-x))^2-2(x-2+a)(x+2-a)}}}<br>
Define y = 2-a<br>
{{{((x+y))^2+((y-x))^2-2(x-y)(x+y)}}}<br>
Now define m = x+y and n = x-y<br>
{{{m^2+n^2-2mn = m^2-2mn+n^2 = (m-n)^2}}}<br>
Now go back and replace m, n, and y with their equivalent expressions<br>
{{{(m-n)^2=((x+y)-(x-y))^2=(2y)^2 = 4y^2=4(2-a)^2}}}<br>
ANSWER: 4(2-a)^2 or, equivalently, 4(a-2)^2<br>