How to calculate the final velocity of an object with the initial velocity, change in time and, constant acceleration

To know the final velocity of an object, multiply the acceleration by how long was the acceleration constant or by a given amount of time. Then add the product to the initial velocity. For example, if the initial velocity is -15 meter per second and the acceleration is 5 meters per second squared , the final velocity after 7 seconds is 5 meters per second squared multiplied by 7 seconds is 35 plus the initial velocity of -15 meters per second, means the final velocity is 20 meters per second.