Respuesta :
Answer: [tex]13^2=x^2+(x+7)^2[/tex] is used to find 'x'.
Step-by-step explanation:
Let the length of other leg be 'x'.
Since we have given that one of the legs needs to be 7 feet longer than the other leg.
So, Length of one leg = x+7
Hypotenuse of the right triangle = 13 feet.
Since it form right angle triangle.
so, we can use "Pythagorus theroem".
[tex]13^2=x^2+(x+7)^2\\\\169-(x+7)^2=x^2\\\\169-(x^2+49+14x)=x^2\\\\169-x^2-49-14x=x^2\\\\120-14x=2x^2\\\\60-7x=x^2\\\\x^2+7x-60=0\\\\x^2+12x-5x-60=0\\\\x(x+12)-5(x+12)=0\\\\(x+12)(x-5)=0\\\\x=5[/tex]
Hence, [tex]13^2=x^2+(x+7)^2[/tex] is used to find 'x'.