Đáp án:
$\\$
`Q = (1/14 - 1/30 - 1/46)/(2/35 - 2/75 - 2/145) ÷ (3/8 - 15/17 + 30/31)/(1/6 - 20/51 + 40/93)`
`-> Q = (5/70 - 5/150 - 5/230)/(4/70 - 4/150 - 4/230) ÷ (30/80 - 30/34 + 30/31)/(40/240 - 40/102 + 40/93)`
`-> Q = (5 (1/70 - 1/150 - 1/230) )/(4 (1/70 - 1/150 - 1/230) ) ÷ (30 (1/80 - 1/34 + 1/31) )/(40/3 (1/80 - 1/34 + 1/31) )`
`-> Q = 5/4 ÷ 30/(40/3)`
`-> Q =5/4 ÷ (30 ÷ 40/3)`
`->Q = 5/4 ÷ (30 × 3/40)`
`->Q = 5/4 ÷ 9/4`
`-> Q=5/4× 4/9`
`-> Q=5/9`
Vậy `Q=5/9`
