Which of the following expressions is equivalent to b(b-3) - 7(2 + b) ?

In a column proof the right column states your reasons

The serenity and the mystic are sail boats. the serenity and the mystic start at the same point and travel away from each other in opposite directions. the serenity travels at 16 mph and the mystic travels at 19 mph. how far apart will they be in 3 hours?

Y= 4x + 3 y = - 1 4 x - 5 what is the best description for the lines represented by the equations?