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## Comment on

3x-5## I did it a different way. I

Then we can write x + 15 = 180 - (3x-5)

Solve for x. x = 42.5

Will that always work or was it a fluke?

## That's a great approach.

That's a great approach.

You first used the fact that angles on a line add up to 180 degrees to determine that the angle above (3x-5) must equal 180 - (3x-5).

Then you used the fact that that angle, 180 - (3x-5), must equal the other angle x + 15.

Perfect!