by definition of supplementary angles. Then, m<5 + m<7 = m<7 + m<9 by the

transitive property of equality.

transitive property of equality.

transitive property of equality. To find the answer to this equation, we need to apply the definitions and properties of supplementary angles.

Supplementary angles are a pair of angles whose measures sum up to 180 degrees.

According to the problem, we have:
m<5 + m<7 = m<7 + m<9

Based on the given information, we can assume that angles 5, 7, and 9 are supplementary to one another.

Now, using the transitive property of addition (not equality), we can rewrite the equation as:
m<5 + m<7 + m<9 = m<7 + m<9 + m<9

Next, we can simplify the equation by combining like terms:
m<5 + m<7 + m<9 = m<7 + 2m<9

So, the equation m<5 + m<7 = m<7 + m<9 can be simplified to m<5 + m<7 + m<9 = m<7 + 2m<9.