A + (-b) where a=4 and b=2 please help

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!

Write numerical coefficient of y² in the expression 2x² - 15xy – 7y²

Given the points a(-2, 1) and b(8, 6), find the coordinates of the point c on directed line segment ab, that partitions ab in the ration 2: 3.