Answer:
x = 5
Step-by-step explanation:
Pythagorean Theorem [tex]a^{2} + b^{2} = c^{2}[/tex]
side a = x
side b = x + 7
side c = x + 8
therefore:
[tex]x^{2} + (x+7)^{2} = (x+8)^{2}[/tex]
This would result in:
[tex]x^{2} + x^{2} + 14x + 49 = x^{2} + 16x + 64[/tex]
Let's combine our like terms:
[tex]2x^{2} + 14x + 49 = x^{2} +16x + 64[/tex]
This looks like a mess, but now we need to take all the value from the right side and move them to the left side using inverse operations. This would result in:
[tex]2x^{2} - x^{2} + 14x - 16x + 49 - 64 = 0[/tex]
Again, combine like terms:
[tex]x^{2} - 2x - 15 = 0[/tex]
Now we factor:
(x-5)(x+3) = 0
Solving gives us:
x - 5 = 0 or x = 5 and x+3 = 0 or x = -3
Since we cannot have a negative distance we can discard the -3.
We plug in the 5 for X making the following:
Side a = 5
Side b = 12
Side c = 13
Check our Work
[tex]5^{2} + 12^{2} = 13^{2}[/tex]
25 + 144 = 169
169 = 169 is true so x is indeed 5.
Whew!