If an item costs $0.42 per ounce and the total cost of the item is $6.72, how many ounces are in the item?

Celeste wants to have her hair cut and permed and also go to lunch. she knows she will need $50. the perm cost twice as much as her haircut and she needs $5 for lunch. how much does the perm cost?

The difference of three and the reciprocal of a number is equal to the quotient of 20 and the number. find the number.

Which expressions equal 9 when x=4 and y=1/3 a. x2+6y b. 2x + 3y c. y2-21x d. 5 (x/2) -3y e. 3x-9y