13x^2-16x=x^2-x

Can someone help solve this in using the quadratic formula

What properties allow transformation to be used as a problem solving tool

If the cost to mail a package is an initial $5 and $0.28 for every pound the total cost to mail a package was $11.27, how much did the package weigh?

Li buys supplies so he can make and sell key chains. he begins to make a profit only after he sells 4 key chains. what point on the graph makes the most sense in this situation?