Respuesta :

Angles on a straight line add up to 180 degrees so

45 + 3x = 180
Subtract 45 from both sides to remove the 45 on the left

3x = 135
Then divide both sides by 3
x = 45

Answer is X = 45

Answer:

45 + 3x = 180

x = 45

Step-by-step explanation:

45 + 3x = 180

3x = 180 - 45

3x = 135

x = 135/3

so, x = 45