find the value of (5/6(1/2+2/3+3/4-4/5))/1/8 in the lowest form

for the additions, the common denominator is 60

grind out the sum of the inner bracket
then multiply that by 5/8,
simplify if needed
finally multiply that by 8

let me know what you got, so I can check it for you

btw, are you sure that -4/5 is not supposed to be +4/5 ??
It would fit the pattern more.