7 and -3 are the roots of the quadratic equation x^2+kx-21=0 what is the value of k

Twenty-five percent of the customers entering a grocery store between 5 p.m. and 7 p.m. use an express checkout. consider five randomly selected customers, and let x denote the number among the five who use the express checkout.

How do i get my dad to stop making me gargle his pickle i want my mom to gargle my pickle not my dads

Answer each of the questions for the following diagram: 1. what type of angles are these? 2. solve for x. what does x equal? 3. what is the measure of the angles?