How do I determine if each equation is non linear? Which ones are linear, and which ones aren't?

y = x/2 - 19, 3y = x^2, 13y = 1/3x + 5, y = x + 25/5, y^3 = x

Started: jun 20 at 10: 35pm quiz instructions question 3 y 2x+4 graph the system of linear inequalities 1 by < 2x-2 ty

Aclass consists of 55% boys and 45% girls. it is observed that 25% of the class are boys and scored an a on the test, and 35% of the class are girls and scored an a on the test. if a student is chosen at random and is found to be a girl, the probability that the student scored an ais

Which points are solutions to the linear inequality y < 0.5x + 2? check all that apply. (–3, –2) (–2, 1) (–1, –2) (–1, 2) (1, –2) (1, 2)