What is the y-intercept of the linear equation x-1/2y=-6

The pressure exerted on the walls of a container by a gas enclosed within it is directly proportional to the temperature of the gas. if the pressure is 6 pounds per square inch when the temperature is find the pressure exerted when the temperature of the gas is 380 degrees f show work for the

Find the value of p for which the polynomial 3x^3 -x^2 + px +1 is exactly divisible by x-1, hence factorise the polynomial

Ineed to know the answer to this algebra question.