Find the diffrence between 7/8 and 1/2 and find the sum of 1/5 and 2/3

Answer asap. you begin with 1/2 scoop of ice cream. since you're hungry, you ask the vendor for 2/7 more scoops of ice cream. then, you eat 5/8 scoops. how many scoops of ice cream are left on your cone? i will mark brainliest for first correct answer.

Why is causation so much more difficult to prove than correlation?

If f(x) = 3x-2 and g(x) =2x+1 find (f-g)(x)