7 less than a number t written as an algebraic expression

Create a real-life situation and create a system and show how it might be modeled algebraically with a system of equations (or inequalities) show all work include a few sentences explaining the situation, your variables of choice and what each represents, and how you would set it up and solve it algebraically. !

Can somebody me out with this question

Which segments are congruent? o jn and ln o jn and nm o in and nk onk and nm