0,57:1,9•4,4-0,68:1,17:0,4=

Interpretation (European notation): 0,57:1,9•4,4-0,68:1,17:0,4 = (0,57 ÷ 1,9) × 4,4 − (0,68 ÷ 1,17 ÷ 0,4)

Compute:

• A = 0,57 ÷ 1,9 = 0,30; A × 4,4 = 0,30 × 4,4 = 1,32
• B = 0,68 ÷ 1,17 ÷ 0,4 = (0,68 ÷ 1,17) ÷ 0,4 = (68/117) ÷ (4/10) = (68/117) × (10/4) = 170/117 ≈ 1,45299

Result: 1,32 − 1,45299 ≈ -0,13299

Exact fraction: 1,32 is 627/475 and 1,45299 is 170/117, so the difference is -389/2925 ≈ -0,13299.

Final (decimal): approximately -0,133 (to three decimals). Final (exact): -389/2925.