On ixl.com, at level 6, do 15 problems in each of skills Z.1 and Z.2. In these skills, you will be substituting values in for variables to determine if each is a solution for the given equations. Please use a piece of notebook paper to show your work. Label one side with Z.1, and number each problem that you solve. Label the other side Z.2, and number each problem you solve for this skill.