Respuesta :

15^2 = x^2 + 11^2

225 = x^2 + 121

Subtract both sides 121

225 - 121 = x^2 + 121 - 121

104 = x^2

x = √104

x = √4 × 26

x = √4 × √26

x = 2 × √26

x = 2 √26