diff --git a/src/main/java/com/github/pedrovgs/problem74/BubbleSort.java b/src/main/java/com/github/pedrovgs/problem74/BubbleSort.java
index d8cb56e6..f04d2fab 100644
--- a/src/main/java/com/github/pedrovgs/problem74/BubbleSort.java
+++ b/src/main/java/com/github/pedrovgs/problem74/BubbleSort.java
@@ -25,6 +25,7 @@
  */
 public class BubbleSort extends SortingAlgorithm {
 
+
   /**
    * Bubble sort, sometimes referred to as sinking sort, is a simple sorting algorithm that
    * repeatedly steps through the list to be sorted, compares each pair of adjacent items and swaps
diff --git a/src/test/java/com/github/pedrovgs/problem20/MultiplicationWithoutMultiplyTest.java b/src/test/java/com/github/pedrovgs/problem20/MultiplicationWithoutMultiplyTest.java
index b022e231..a94b842b 100644
--- a/src/test/java/com/github/pedrovgs/problem20/MultiplicationWithoutMultiplyTest.java
+++ b/src/test/java/com/github/pedrovgs/problem20/MultiplicationWithoutMultiplyTest.java
@@ -46,4 +46,30 @@ public class MultiplicationWithoutMultiplyTest {
   @Test public void shouldTakeIntoAccountNegativeNumbers() {
     assertEquals(-14, multiply.calculate(-2, 7));
   }
+
+  /**
+   * This tests for Testing HomeWord - Dinh The Hiep - 17020731
+   */
+
+  //Testing with both negative n1,n2 (n1 < 0, n2 < 0)
+  @Test
+  public void test1() {
+    assertEquals(5600, multiply.calculate(-70,-80));
+  }
+  //Testing with n1 > 0, n2 >0
+  @Test
+  public void test2() {
+    assertEquals(484, multiply.calculate(44, 11));
+  }
+  //Testing with n1 > 0, n2 < 0
+  @Test
+  public void test3() {
+    assertEquals(-1500, multiply.calculate(500, -3));
+  }
+  //Testing with n2 > 0, n1 < 0
+  @Test
+  public void test4() {
+    assertEquals(-4500, multiply.calculate(3, -1500));
+  }
+
 }
diff --git a/src/test/java/com/github/pedrovgs/problem74/BubbleSortTest2.java b/src/test/java/com/github/pedrovgs/problem74/BubbleSortTest2.java
new file mode 100644
index 00000000..ced7e2e6
--- /dev/null
+++ b/src/test/java/com/github/pedrovgs/problem74/BubbleSortTest2.java
@@ -0,0 +1,45 @@
+package com.github.pedrovgs.problem74;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+public class BubbleSortTest2 {
+    @Test
+    public void Intsort(){
+        int[] input = { 1, 2, 4, 3 };
+        int[] expectedArray = { 1, 2, 3, 4 };
+        BubbleSort bubbleSort = new BubbleSort();
+        bubbleSort.sort(input);
+        assertArrayEquals(expectedArray,input);
+    }
+
+    @Test
+    public void Doublesort(){
+        int[] input = {-100,63,-62,6};
+        int[] expectedArray = { 1, 2, 3, 4 };
+        BubbleSort bubbleSort = new BubbleSort();
+        bubbleSort.sort(input);
+        assertArrayEquals(expectedArray,input);
+    }
+
+    @Test
+    public void Randomsort(){
+        int[] input = { 5,-541,56,45,26};
+        int[] expectedArray = { 1, 2, 3, 4 };
+        BubbleSort bubbleSort = new BubbleSort();
+        bubbleSort.sort(input);
+        assertArrayEquals(expectedArray,input);
+    }
+
+    @Test
+    public void RanDomsort(){
+        int[] input = { 10,559,-65,622,-65,-6};
+        int[] expectedArray = { 1, 2, 3, 4 };
+        BubbleSort bubbleSort = new BubbleSort();
+        bubbleSort.sort(input);
+        assertArrayEquals(expectedArray,input);
+    }
+
+
+}
\ No newline at end of file