Which phrase describes an unknown or changeable quantity

What expression is equivalent to 42x-56y

Jenny earned a 77 on her most recent test jenny score is no less then 5 points greater then 4/5 of terrance’s score if t represents terrance score which inequality represents the situation

Write an equation of the line that passes through the point (2, 3) and is perpendicular to the line x = -1. a) y = 1 b) y = 3 c) y = 0 eliminate d) y = -3