Respuesta :

Answer:

x = 3

Step-by-step explanation:

• the diagonals of an isosceles trapezoid are congruent , then

11x - 6 = 3x + 18 ( subtract 3x from both sides )

8x - 6 = 18 ( add 6 to both sides )

8x = 24 ( divide both sides by 8 )

x = 3