Which substitution method should be the best used to solve which system of equations

Rob filled 5 fewer plastic boxes with football cards than basketball cards. he filled 11 boxes with basketball cards.

Jacob is graphing the line represented by the equation  −6x−5y=12.−6x−5y=12.  he first plots the  x-x-  and  y-interceptsy-intercepts  as follows.    which statement is correct regarding the intercepts on the graph?

P= price tax is 4% added to the price. which expression shows the total price including tax?