quantity: there will result a new group containing two equations less than the original group. III. Continue the operation until a single equation is found, containing but one unknown quantity. IV. Find the value of this unknown quantity by the preceding rules; substitute this in either one of the group of two equations, and find the value of a second unknown quantity; substitute these in either of the group of three, finding a third unknown quantity; and so on, till the values of all are found. In making the combinations, care should be taken to make them in such a way as to obtain as simple equations as possible. If any unknown quantity does not enter all of the equations, it will generally be best to eliminate that quantity first. |