Really confused, please help ^^

What basic trigonometric identity would you use to verify that sin x cos x tan x =1-cos^(2)x?

Which of the following system of equation is not equal to the system of equations is not equal to the system of equations shown below

2y= 3 2 x−2 y = − 1 3 x + 1 y=− 3 1 x+1