Please Everybody I Have a Hovework and I don't do this homework

Please Post here

1. show that

Sin (x+Y+z)=Sin x Cos y Cos z+ Cos x Sin y cos z + cos x cos y sin z-sin x

Sin y sin z

Cos (x+y+z)= Cos x Cos y Cos z- Sin x Sin y Cos z-Sin x Cos y Sinz- Cos x

Sin y Sin z

Please help my HOmework

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