How do you solve word equation C6H14 plus O2----CO2 plus H20?

Include constants x,y,z as in xC6H14 + yO2 = zCO2 + H2O (notice the number of constants is 1 less than the number of terms). Then equate numbers of like atoms on each side, because atoms are not created or destroyed. So for Oxygen you get 2y=2z+1 and using the other atoms you'll get more equations. Solve these as a set of simultaneous equations. If you get fractions in the answers, multiply all by one same number (ie equally) to get rid of them. That's how.