The first method is to use
factorization:
The original equation is:
x^2-4x+3=0
We'll write 3 as the difference 4 - 1 =
3
We'll re-write the equation, changing 3 with the
difference:
x^2-4x+4-1=0
Now,
we'll combine the first and the last terms and the middle
terms:
(x^2 - 1) - (4x - 4) =
0
We'll write the difference of squares as a
product:
x^2 - 1 =
(x-1)(x+1)
We'll factorize (4x - 4) by
4:
(4x - 4) = 4(x-1)
Now,
we'll re-write the equation:
(x-1)(x+1) - 4(x-1) =
0
We'll factorize by (x-1) and we'll
get:
(x-1)(x+1-4) = 0
We'll
set each factor as zero:
x - 1 =
0
We'll add 1 both sideS:
x =
1
x - 3 = 0
We'll add 3 both
sides:
x = 3
The
roots of the equation are: {1 ;
3}.
The second method is to
apply the quadratic formula:
x1 =
[-b+sqrt(b^2-4ac)]/2a
x1 =
[4+sqrt(16-12)]/2
x1 =
(4+2)/2
x1 =
3
x2 =
(4-2)/2
x2 =
1
As we can see, we've get the
same result!
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