Answer:
X = 5
Step-by-step explanation:
You need to use the Pythagorean theory to solve this question.
[tex] {13}^{2} = {x}^{2} + {(x + 7)}^{2} [/tex]
[tex]169 = {x}^{2} + ( {x}^{2} + 14x + 49)[/tex]
[tex]169 = 2 {x}^{2} + 14x + 49[/tex]
[tex]0 = 2 {x}^{2} + 14x + 49 - 169[/tex]
[tex]0 = 2 {x}^{2} + 14x - 120[/tex]
Now simply the equation by dividing everything by 2.
[tex]0 = {x}^{2} + 7x - 60[/tex]
[tex]0 = (x - 5)(x + 12)[/tex]
Now, you can find the possible solutions by setting each bracket to 0.
[tex]0 = x - 5[/tex]
[tex]5 = x[/tex]
OR
[tex]0 = x + 12[/tex]
[tex] - 12 = x[/tex]
However, a measurement on a triangle cannot be negative. Therefore, we can ignore -12 and say that the answer is x = 5.
