This Instructional Activity is a part of the Lesson 6, Unit 1, Grade 8. Ask advanced learners to consider why it is necessary to restrict the values of x and y to nonzero numbers. They should be able to respond that if x or y is a negative integer, the value of the expression could depend on division by zero, which is undefined. The goal of this lesson is to show why the laws of exponents, (10)-(12), are correct for all integers a and b and for all nonzero x and y. We recall (10)-(12).