Respuesta :

Answer:

The answer is x = 5.

Step-by-step explanation:

Given:

Δ ABC is an Isosceles triangle with AB = CA

   m∠ ABC = ( 6x + 4 )°

   m∠ BAC = 73°

   m∠ BCA = ( 8y - 7 )°

To Find:

x = ?

Solution:

Properties of an Isosceles Triangle.

  1. Base angles or two angles are equal.
  2. Any two sides are equal.

Here , Δ ABC is an Isosceles triangle with AB = CA

∴  m∠ BAC = m∠ BCA

[tex]73= 8y-7\\8y=73+7\\8y=80\\y=\frac{80}{10} \\y=10[/tex]

∴      m∠ BCA = ( 8y - 7 )°

                       = 8 × 10 - 7

       m∠ BCA  = 73  Which is same as ∠ CAB

Property of a Triangle is Sum of the measures of the angle of a triangle is 180°.

[tex]\angle ACB + \angle CAB + \angle CBA = 180[/tex]

Substituting the values we get,

[tex]73 + 73 + (6x+4) = 180\\6x+4=180-146\\6x=34-4\\6x=30\\x=\frac{30}{6} \\x=5\\[/tex]

The answer is x = 5.