Added Step 5 and updated step 3

Step 5 - Delete the backup database/Step 5 - Delete the backup database.json

@@ -0,0 +1,76 @@
+{
+  "$schema": "http://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
+  "contentVersion": "1.0.0.0",
+  "parameters": {
+    "factoryName": {
+      "type": "string",
+      "metadata": "Data Factory name"
+    }
+  },
+  "variables": {
+    "factoryId": "[concat('Microsoft.DataFactory/factories/', parameters('factoryName'))]"
+  },
+  "resources": [
+    {
+      "name": "[concat(parameters('factoryName'), '/Step 5 - Delete the backup database')]",
+      "type": "Microsoft.DataFactory/factories/pipelines",
+      "apiVersion": "2018-06-01",
+      "properties": {
+        "description": "This pipeline will drop the backup database.",
+        "activities": [
+          {
+            "name": "Delete the backup database",
+            "type": "WebActivity",
+            "dependsOn": [
+            ],
+            "policy": {
+              "timeout": "7.00:00:00",
+              "retry": 0,
+              "retryIntervalInSeconds": 30,
+              "secureOutput": true,
+              "secureInput": true
+            },
+            "userProperties": [
+            ],
+            "typeProperties": {
+              "url": {
+                "value": "https://management.azure.com/subscriptions/@{pipeline().parameters.infra_SubscriptionId}/resourceGroups/@{pipeline().parameters.infra_BackupResourceGroup}/providers/Microsoft.Sql/servers/@{pipeline().parameters.infra_BackupSqlServerName}/databases/@{pipeline().parameters.synapse_DatabaseBackupName}?api-version=2019-06-01-preview",
+                "type": "Expression"
+              },
+              "method": "DELETE",
+              "headers": {
+                "Content-Type": "application/json"
+              },
+              "authentication": {
+                "type": "MSI",
+                "resource": "https://management.azure.com/"
+              }
+            }
+          }
+        ],
+        "parameters": {
+          "infra_BackupSqlServerName": {
+            "type": "securestring"
+          },
+          "synapse_DatabaseBackupName": {
+            "type": "securestring"
+          },
+          "infra_SubscriptionId": {
+            "type": "securestring"
+          },
+          "infra_BackupResourceGroup": {
+            "type": "securestring"
+          }
+        },
+        "folder": {
+          "name": "Backup DW"
+        },
+        "annotations": [
+        ],
+        "lastPublishTime": "2019-09-19T14:34:59Z"
+      },
+      "dependsOn": [
+      ]
+    }
+  ]
+}