Pls help! I will mark the first person who answers BOTH questions first!!

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

Which of the following expressions is equal to 2x^2+8

Marco has $38.43 dollars in his checking account. his checking account is linked to his amazon music account so he can buy music. the songs he purchases cost $1.29. part 1: write an expression to describe the amount of money in his checking account in relationship to the number of songs he purchases. part 2: describe what the variable represents in this situation.