You have to figure out a way to make 195° using 
the sum or difference of two special angles from this list:

30°, 45°, 60°, 90°, 120°, 135°, 150°, 180°, 210°, 
225°, 240°, 270°, 300°, 315°, 330°.

You can write 195° as any one of these:

150°+45°, 135°+60°, 225°-30°, 240°-45°, 315°-120°, 330°-135°

If you choose to use the first one, 150°+45°, you then use



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Let's convert that to degrees:

°

Then we can write 75° as 30°+45°

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Then we can use the identity: 

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Rationalize the denominator:



Indicate multiplication of numerators and denominators:



Multiply out the bottom:

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Move the negative sign out front, and cancel the 4's

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Edwin