Three times the difference of four times a number and three times  a second number is .

Let be a first number and be a second number.

Hence the equation is .

Four times the sum of times the second number and times the first number is .

Hence the equation is .

The system of equations are and .

Solve the system of equations by elimination method.

Step 1:

Multiply each equation with a suitable multiplier.

Case (i):

          (First equation)

      (Divide each side by )

                   (Cancel common terms)

         (Multiply each side by )

                   (Multiply)

Case (ii):

             (Second equation)

         (Divide each side by )

                   (Cancel common terms)

Step 2:

Add the equations to eliminate the one variable.

                    (Divide each side by )

                                (Cancel common terms)

Step 3:

Substitute into any original equation to find value. 

                   (Second equation)

                 (Substitute )

                   (Multiply)

   (Subtract from each side)

                        (Apply additive inverse property: )

                   (Divide each side by )

                            (Cancel common terms)

The solution of the system is .

The solution of the system is .