2x-(x+2)(x-2)=5-(x-1)2

2x - (x^2 - 4) = 5 - (x^2 - 2x + 1)
2x - x^2 + 4 = 5 - x^2 + 2x - 1
2x - x^2 + x^2 - 2x = 5 - 1 - 4
0=0