What single percentage change is equivalent to 13% increase followed by 19% increase

You can find the constant of proportionality by finding the ratio of

Fanny mendelssohn manages all the magazines and paperback books at a local grocery store. she prices many paperbacks to sell at $7.99. the cost to the store is $5.29. what is the markup rate on a paperback book, based on its cost?

Write the expression 7x^3-28xy^2 as the product of 3 factors