please answer questions with clear and precise answers all answers must have clear steps

You must show all your work: no credit will be given for merely presenting the final answer without a complete solution. You need to show how your solution was developed: specifically, how each next line is obtained from the previous one. Making your solution obscure or ambiguous will never help you receive a better score.
You need to state every physics law which you use to solve the problem and define every quantity in your equation (F1,net – the net force acting on mass M1, D12 is the distance between the masses etc.). Even though the amount of text in your exam solutions should be kept to a minimum, some crucial explanations are absolutely necessary.
Making a schematic picture (or graph) and showing all the quantities on it is not mandatory but strongly preferable and will definitely help me understand your work. This is specifically important if your solution is not complete.
Each of your calculations should have a formula (a mathematical expression in a general form), the numbers with their units and your final answer with the proper unit. It is completely acceptable to substitute numbers at the beginning of your calculation and to solve your equations in the numerical form. SI units should always be used unless otherwise instructed and the correct units are absolutely necessary for all parts of your calculation