Respuesta :

Answer:

a.

2x+4x+3x=180 sum of interior angle of the triangle is 180

9x=180

x=180/9=20

b.

x-20+x+10+x-20=180sum of interior angle of the triangle is 180

3x-30=180

3x=180+30

x=210/3=70

c.x+10+x+20+x=180 linear pair

3x+30=180

3x=180-30

x=150/3=50

Answer:

A: x=20

Step-by-step explanation:

angles in a triangle always equal 180° so knowing this 2x+3x+4x=180

9x=180

9x÷9=x

180÷9=20