A 50 cm length of ribbon costs x dollars. Find an expression for the cost of y meters of ribbon. Give your answer to its simplest form.
My solution:
Let y = the total cost for a certain amount of x ribbons
Let x = the cost per ribbon
I write a linear equation to express a relation between x, y and 50.
I say the equation is y = 50x.
Is this correct? If not, why not?