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°−135°=180° 9 x minus 135 equals 180 9x°+135°=180° 9 x plus 135 equals 180 9x°+135°=90° 9 x plus 135 equals 90 9x°=180°

Answer 1

To set up the equation for the problem, we need to remember that supplementary angles are two angles whose measures add up to 180°. Given the measures of the angles:

• m∠ABC = 135°
• m∠CBD = 9x°

We can express this relationship as:

m∠ABC + m∠CBD = 180°

Substituting in the known values:

135° + 9x° = 180°

Now, the correct equation to solve for x is:

\[ 9x° + 135° = 180° \]

So, the answer is:

9x° + 135° = 180°