Sum means addition
negative 18 means -18
a number can be x
Sum of negative 18 and x should be 11
thus the equation is
Answer and Step-by-step explanation:
Since we have given that
1. m∠1 + m∠5 = 180° and m∠1 + m∠4=180° - Given
2. m∠1 + m∠5 = m∠1 + m∠4 - Substitution
3. m∠5 = m∠4 -
Subtraction property of equality
4. Ray YZ is parallel to Ray UV - If alternate interior angles equal, then line are ||