Can anyone help me if you get it right i'll give 30!

If a =6, what is the value of 2a(3b + 5c)?

While scuba diving, rajeev dove to a depth of 12.6 feet below the surface of the water and then descended another 8.7 feet. what expression can be used to find rajeev's new position? 12.6 – 8.7 –12.6 – 8.7 –12.6 – (–8.7) 12.6 – (–8.7)

Maria walks a round trip of 0.75 mile to school every day.how many miles will she walk in 4.5 days