How to solve and answer please

Write a real-world solution that can be represented by the equation y = 7x be sure to explain what the variables represented in the solution

Which matrix can be multiplied to the left of a vector matrix to get a new vector matrix ?

Which unit of measure would be the most appropriate to measure the capacity of a bottle of nail polish? a. fluid ounces b. cups c. pints d. quarts e. gallons