To find the value of the expression 8•(2x+5)-4x when x=1.75, we simply substitute x with 1.75 and solve:

8•(2(1.75)+5)-4(1.75)
8•(3.5+5)-7
8•8.5-7
68-7
61

Therefore, the value of the expression 8•(2x+5)-4x when x=1.75 is 61.