Identity matrices and inverses

Connect identity matrices, inverses and linear systems in this precalculus practice set. Begin with compatible identity dimensions, then verify candidate inverses and compute a small inverse through solution equations. Single-select and multiselect questions distinguish invertible and singular matrices, solve both left- and right-sided matrix equations, and test when cancellation is justified. Detailed explanations preserve multiplication order and check results against the original equations. No determinant technique is required; row operations and matrix products provide the reasoning.