How can you find the sales tax for a purchase ? explain

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.

Marcus needs to rewrite f(x) = x2 + 6x + 4 in vertex form.

What is the reflection image of (5,-3) across the line y = -x?