The equations are

                   Equation (1)

                Equation (2)

Multiply the equation (2) by 6.

             Equation (3)

Subtract the equation (1) and equation (3) to eliminate the x variable

          (Subtraction the corresponding columns)

Apply division property of equality: if a = b, then.

Divide each side by 25.

Substitute in equation (1).

Apply subtraction property of equality: If a = b then a b = b a.

Subtract 3 from each side.

Apply Additive inverse property: .

Apply Additive identity property: .

Apply division property of equality: if a = b, then.

Divide each side by 6.

The solution is .

The solution is .