$4 is what percent of $50?

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.

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)

Answer! if you don’t mind, can you explain