Question

I was never taught how to do this... some one help me.

Answer 1

So cos means adjacent over hypotenuse which would be 15/17 and you can’t simplify it down farther so 15/17 is your final answer.

Answer 2

`$\cos X = \frac{\text{adjacent}}{\text{hypotenuse}} = \boxed{(15)/(17)}$`