Two supplementary angles have the following measures: m∠ABC=135°

Question

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°=180°
9 x equals 180

9x°+135°=90°
9 x plus 135 equals 90

9x°+135°=180°

Answer 1

Two angles are supplementary if their measures add up to 180°. You have the measures of the two angles as follows:

• m∠ABC = 135°
• m∠CBD = 9x°

To find the equation, you can set up the equation based on the property of supplementary angles:

m∠ABC + m∠CBD = 180°.

Substituting the measures you have:

135° + 9x° = 180°.

So the equation to solve for x is:

9x° + 135° = 180°.