Those lines on the sides of x in the equation mean "absolute value". Which is a complicated way of saying "this number will never be negative". So if x = 2 then absolute value x= 2 but if x = -2 then absolute value x still is positive 2. Because of those brackets/lines (whatever they're called). So if you're given x=2 then it's simply saying y=4(2)-1 which is y=7
