k so here is what you do pick one of them and sole for a ariable
9x-8y=8
8y= 8-9x
y=(8-9x)/8
then take the y you got and plug it in or substitute it into the other one
5x-9(8-9x/8)=112
then multiply out the 9
5x-(72-81x)/8 = 112
simplify 5x-9-(81/8)=112
combine like terms
5x-(153/8)= 112
add (153/8) to both sides
5x=(1049/8) x=1049/4 or 26.225
now you take x and plug it into the y to get the y
Man thats an ugly problem hope i helped