The answer is b. she moves 50 miles per hour

If the graphs of the linear equations in a system are parallel, what does that mean about the possible solution(s) of the system? a. there are infinitely many solutions. b. there is no solution. c. there is exactly one solution. d. the lines in a system cannot be parallel.

It says factor each expression 49x-28?

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?