We'll expand the squares using the
formula:
(a+b)^2 = a^2 + 2ab +
b^2
(a-b)^2 = a^2 - 2ab +
b^2
(2x-1)^2 = (2x)^2 - 2*(2x)*1 +
1^2
(2x-1)^2 = 4x^2 - 4x + 1
(1)
(x-3)^2 = x^2 - 2*x*3 +
3^2
(x-3)^2 = x^2 - 6x + 9
(2)
We'll subtract (2) from
(1):
4x^2 - 4x + 1 - x^2 + 6x -
9
We'll combine like
terms:
3x^2 + 2x - 8
We'll
determine the roots of the quadratic:
3x^2 + 2x - 8 =
0
x1 = [-2+sqrt(4+96)]/6
x1 =
(-2+10)/6
x1 = 8/6
x1 =
4/3
x2 = (-2-10)/6
x2 =
-2
The quadratic could be written as a product of linear
factors:
3x^2 + 2x - 8 = 3(x - 4/3)(x +
2)
We'll multiply by 3 the first
factor:
3(x - 4/3)(x + 2) = (3x - 4*3/3)(x +
2)
3x^2 + 2x - 8 =
(3x-4)(x+2)
(2x-1)^2 - (x-3)^2 = (3x-4)(x+2)
q.e.d.
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