Answered By Charles S

Sin(A+B) needs to be expanded using the identity Sin(A+B) = Sin(A)Cos(B) + Cos(A)Sin(B).  As you can see, we weren't given Cos(A) or Sin(B) in the question.  See the whiteboard on how I obtained those values.

Then all you have to do is substitute the values in:

  $\left(\frac{4}{5}\right)\left(\frac{7}{9}\right)+\left(\frac{3}{5}\right)\left(\frac{4\sqrt{2}}{9}\right)$(45 )(79 )+(35 )(4√29 )  

And simplify

 $\frac{28}{45}+\frac{12\sqrt{2}}{45}=\frac{28+12\sqrt{2}}{45}$2845 +12√245 =28+12√245