What is the sum of the greatest number and least number formed by the digits 4,7,0and 9​

Agreeting card company can produce a box of cards for $7.50. if the initial investment by the company was $50,000, how many boxes of cards must be produced before the average cost per box falls to $10.50?

Which graph represents the function f(x)=4[x]?

Does 9q + 7 also equal 7 + 9q ? (simplifying algebraic expressions)