How do we add a fraction in algedra

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

Tamera puts 15/4 gallons of gasoline in her car. which mixed number represents the gallons of gasoline? a) 2 3/4 gallons b) 3 1/4 gallons c) 3 3/4 gallons d) 4 1/2 gallons answer it's worth a lot of points!

Factor -8x3-2x2-12x-3 by grouping what is the resulting expression?