Elimination Method:

The equations are

              Equation (1)

               Equation (2)

Since the coefficients of the m-terms are same, you can eliminate these terms by subtracting the equations. Subtract the equations to eliminate variable m.

Write the equations in column form and subtract the corresponding columns.

   (Write the equations in column form and add)

Now, find the b value by substituting in either equation.

        (Equation 2)

                        (Product of two different signs is negative)

According to addition property of equality: Add 2 to each side.

                  (Apply additive inverse property: )

                        (Apply additive identity property: )

                           (Add: )

According to division property of equality: Divide each side by 4.

                           (Cancel common terms)

                 (Multiply each side by negative one)

                           (Product of two same signs is positive)

                            (Divide: )

The solution is .