This is the symmetric property, for you divide 9 to both sides to get x, instead of adding (addition property of equality)
So symmetric property should be your answer
Hope this helps
Answer:B
Step-by-step explanation:
(3x) + (x+60) = 180
4x + 60 = 180
Subtract 60 from both sides
4x = 120
Divide 4 from both sides
x = 30