I'm relatively new to c++(barely understand what I'm doing). but I tried to make a table. This however, needs some work. I basically made a user input and multiplied everything by eachother. If any of you have time could you tell me a faster or more efficient way of doing this?
You should look into arrays. In looks like you need 1- and 2-dimensional arrays.
Look into arrays to get the idea of how they are accessed and how you can loop over them. Later you may learn how do represent a 2-dimensional array as a 1-dimensional array. This frequently helps with performance.
After you get an understanding of them, then look into std::vector. It is like an array, but is much safer.
Others may think you should skip arrays and go straight to std::vector, but I think for the purpose of understanding how array-type memory is accessed via loops, using a raw array removes some level of complexity.
reuse what you did already:
xxy = 2*xy;
etc...
some compilers can change like 3*3 to 9 and some are less intelligent. I prefer to do it myself so I know it was done, though.
xxxyyy = 9*xy; //one multiplication instead of 4.
side note on style: I can't make sense of what you are doing but the name xxxyyy to me implies x*x*x*y*y*y not 9*xy. Its ok if it makes sense to you and your peers, but to me, the name is very misleading.