N= 18
5/6=15/n you cross multiply them and you get 5n=90
Then you get the n by itself by doing 5n/5 and then you do the same to the other side by doing 90/5 and you get n=18
I could only figure out the partial quotient way im sorry but i think this could help
We know that V = a^3 and that it's 1000 cubic meters (or unit cubes as long as one unit cube is 1x1x1m). We can write the calculation as attached below. The result (dimensions of one cube house) is
10x10x10 meters.
6y + 5*(6 + 7y)
6y + 30 + 35y
41y + 30