Can someone pls help with 1 and 2

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.

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class

Hardest math question of all time can you solve the equation. check for extraneous solutions.9∣9-8x∣ = 2x+3