Answer:
Step-by-step explanation:
Since they are vertical angles, they are equal to each other
3x=80-x
solve
4x=80
x=20
x = 20
==> 3x = 80 - x
=>Pass x to the other side the - sign into to +
==> 3x + x = 80
==> 4x = 80
==>[tex]x = \frac{80}{4} [/tex]
==> 80 ÷ 4
==> x = 20
