evaluate 0.2m + 6 - 4n when m=20 and n= 1/2

If jm equals 5x -8 and lm equals 2x -6 which expression represents jl

Someone this asap for a group of students attends a basketball game. * the group buys x hot dogs at the concession stand for $2 each. * the group buys y drinks at the concession stand for $3 each. the group buys 29 items at the concession stand for a total of $70. how many hot dogs did the group buy?

Me. i can't figure out this question. give an explanation too. .