A mountain is 15,062 feet above sea level, and a valley is 350 feet below sea level, what is the difference in elevation between the mountain and the valley?

Add the two expressions 3.8b - 7 and 2.9b + 9 enter your answer in simplified form

Pls brainliest will be awarded if answer is correct

Gabriel determined that his total cost would be represented by 2.5x + 2y – 2. his sister states that the expression should be x + x + 0.5x + y + y – 2. who is correct? explain.