Two supplementary angles have the following measures: m∠ABC=135° and m∠CBD=9x° . What is the equation to solve for x ?(1 point)

Responses

9x°=180°
9 x equals 180

9x°+135°=90°
9 x plus 135 equals 90

9x°−135°=180°
9 x minus 135 equals 180

9x°+135°=180°