When two musical notes are a "fourth" apart, the frequency of the lower note is 3/4 the frequency of the higher note. using f as the frequency of the higher note, write an expression for the frequency of the lower note. a.) 3/4+f

b.)3/4f

c.) 1/4f

d.) f-1/4

b. x- 48 =120

step-by-step explanation:

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations: