Math
posted by Sasha .
There are 10 sailboats in the harbor. Some of the boats have 2 sail & some of boats have 3 sails. If there are 24 sails visible on all of the boats, how many boats have 3 sails & how many boats have 2 sails?

Set it up like this;
2x + 3y = 24
x + y = 10 <use this one to solve for y.
so y = x + 10 ...
Now substitute (x + 10) for y in the first equation..so
2x + 3(x + 10) = 24
2x + (3x) + 30 = 24
x + 30 = 24
x = 2430 or 6
x = 6, y = 4
so 6 have 2 sails and 4 have 3 sails...