# true or false system comprising two linear equations two variables has unique solution if an

- True or false: A system comprising two linear equations in two variables has a unique solution if and only if the straight lines represented by the equations are nonparallel.
- True or false: Suppose the straight lines represented by a system of two linear equations in two variables are parallel to each other. Then the system has infinitely many solutions.
- True or false: If
*A*and*B*are matrices of the same order, then . - True or false: If
*A*and*B*are matrices such that*AB*and*BA*are both defined, then*A*and*B*must be square matrices. - True or false: If
*A*is a square matrix with inverse and*c*is a nonzero real number, then . - True or false: If
*AX = B*is a system of*n*linear equations in*n*unknowns and does not exist, then*AX = B*does not have a unique solution.