Explanation: First equation can be arranged as: 4 x − 7 = y Put this y into the second equation (instead of y use 4 x − 7 ): 2 x − 3 ( 4 x − 7 ) = − 9 2 x − 12 x + 21 = − 9 − 10 x = − 9 − 21 − 10 x = − 30 x = 3 y can be obtained using the first equation: y = 4 x − 7 y = ( 4 × 3 ) − 7 y = 12 − 7 y = 5 Your solution x = 3
