Which property justifies this statement ?
if x = -2 then 5x = -10.
multiplication property of equality
subtraction property of equality
symmetric property of equality
transitive property of equality

i believe the answer is the polygon, heptagon.

take the logarithm of both sides (the base of the log doesn't matter):

apply the exponent property - this says that :

distribute the log terms on both sides:

group like terms together:

divide through both sides by the coefficient on :

you can do some additional rewriting here using the properties of the logarithm to simplify things if you like: