Simplify the variable expression by evaluating it's numerical part m-8+143-5 and how did get m

Amber had 1/6 of a pie left after the bake sale. rihanna had 3/8 of a pie left. what fraction of a pie did they have altogether?

What effect would doubling all the dimensions of a triangular pyramid have on the volume of the pyramid? explain your reasoning.

Is triangle jkl congruent to triangle rst? if so, what is the scale factor?