diff --git a/Exercises/1-remove.js b/Exercises/1-remove.js
index 82fba07..c655919 100644
--- a/Exercises/1-remove.js
+++ b/Exercises/1-remove.js
@@ -1,7 +1,8 @@
 'use strict';
 
 const removeElement = (array, item) => {
-  // Remove item from array modifying original array
+  const index = array.indexOf(item);
+  return index !== -1 ? array.splice(index, 1) : array;
 };
 
 module.exports = { removeElement };
diff --git a/Exercises/2-elements.js b/Exercises/2-elements.js
index 8518c71..f7f60bc 100644
--- a/Exercises/2-elements.js
+++ b/Exercises/2-elements.js
@@ -1,7 +1,11 @@
 'use strict';
 
 const removeElements = (array, ...items) => {
-  // Remove multiple items from array modifying original array
+  for (const i of items) {
+    const index = array.indexOf(i);
+    if (index !== -1) array.splice(index, 1);
+  }
+  return array;
 };
 
 module.exports = { removeElements };
diff --git a/Exercises/3-unique.js b/Exercises/3-unique.js
index b738823..85c4eeb 100644
--- a/Exercises/3-unique.js
+++ b/Exercises/3-unique.js
@@ -3,6 +3,12 @@
 // Create and return a new array without duplicate elements
 // Don't modify initial array
 
-const unique = array => [];
+const unique = array => {
+  const arr = [];
+  for (const item of array)
+    if (!arr.includes(item)) arr.push(item);
+  return arr;
+};
 
 module.exports = { unique };
+
diff --git a/Exercises/4-difference.js b/Exercises/4-difference.js
index 37d24ab..3f5c97a 100644
--- a/Exercises/4-difference.js
+++ b/Exercises/4-difference.js
@@ -3,6 +3,12 @@
 // Find difference of two arrays
 // elements from array1 that are not includes in array2
 
-const difference = (array1, array2) => [];
+const difference = (array1, array2) => {
+  const arr = [];
+  for (const item of array1) {
+    if (!array2.includes(item)) arr.push(item);
+  }
+  return arr;
+};
 
 module.exports = { difference };