Find derivative of x cube minus y cube equals y with steps please ​

Need on this geometry question. explain how you did it.

M.xyz =radians. covert this radian measure to its equivalent measure in degrees.

Can some one explain how to slove specifically, what is the value of x? 0.9(x+1.4)-2.3+0.1x=1.6 enter the answer as a decimal in the box. x= ?