Berta worked to solve a system of equations. 4x + y = –5 x – y = –5 Step 1: ??? Step 2: x = –2 Step 3: 4(–2) + y = –5 Step 4: –8 + y = –5 Step 5: y = 3 Berta determined that the solution is (–2, 3). Which could have been the equation Berta found in step 1? 4x = 0 5x = 10 5x = –10 5x = –25