Answer: x = 10
Step-by-step explanation:
The Pythagorean's theorem says that for a triangle rectangle with catheti A and B, and with hypotenuse H, we have:
A^2 + B^2 = H^2
In this case, we have:
A = (x - 4)
B = (x - 2)
H = x
Then we have the equation:
(x - 4)^2 + (x - 2)^2 = x^2
Now we need to solve this for x, first let's simplify it.
(x^2 - 2*x*4 + 16) + (x^2 - 2*2*x + 4) = x^2
2*x^2 - 12*x + 20 = x^2
2*x^2 - 12*x + 20 - x^2 = 0
x^2 - 12*x + 20 = 0
The solutions of this equation are given by the Bhaskara's equation, such that for an equation like:
a*x^2 + b*x + c = 0
The solutions are:
[tex]x = \frac{-b \pm \sqrt{b^2 - 4*a*c} }{2*a}[/tex]
Then the solutions for our equation are:
[tex]x = \frac{-(-12) \pm \sqrt{(-12)^2 - 4*1*20} }{2*1} = \frac{12 \pm 8 }{2}[/tex]
Then the two possible solutions are:
x = (12 - 8)/2 = 4/2 = 2
Notice that if x = 2, then the length of the catheti will be:
A = 2 - 4 = -2
B = 2 - 2 = 0
This has no sense, so we can discard this solution.
The other solution for x is:
x = (12 + 8)/2 = 10
x = 10
Then:
H = 10
A = 10 - 4 = 6
B = 10 - 2 = 8
This solution makes sense, then x = 10.
