Tahnks for helping it will mean a lot

How do i put 3(x+7) in distributive property

Amountain climber starts a climb at an elevation of 453 feet above sea level at his first rest stop he has climbed 162 feet and by his second rest stop he has climbed another 207 feet its getting late in the day so the climber starts his way down if the climber desends 285 feet how much does he need to ascend or descend to return to the original starting point

Acontainer holds 0.7 liters of oil and vinegar. 3/4 of the mixture is vinegar. how many liters of oil are in the container? express your answer as both a fraction and a decimal.