Question 509148
Let's add some parenthesis to emphasize order of operations here.

5/6+(2/3*3/4)-(1/4*2/5)

Left most parenthesis:

(2/3) * (3/4)  cancel out the threes to get (2/4) which reduces to 1/2.

Right most parenthesis

(1/4) * (2/5)  cancel out the 2, reduce the 4 to a 2  to get  (1/(2*5)) = 1/10.

so we have  (5/6) + (1/2) - (1/10)

Least Common Multiple of 6,12 and 10 is 60.

(50/60) + (30/60) - (6/60) =  74/60 (reduces to)  37/30 <---- Answer