Đáp án:
`A = (-11)/23 × 10/13 + 11/(-13) ÷ (-3)/23 - (-12)/23`
`⇔ A = (-11)/23 × 10/13 + (-11)/13 × (-23)/3 + 12/23`
`⇔ A = (-110)/299 + 253/39 + 12/23`
`⇔ A = (-330)/897 + 5819/897 + 468/897`
`⇔ A = (-330 + 5819 + 468)/897`
`⇔ A = 259/39`
Vậy `A = 259/39`
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`B = (-5)/6 ÷ ( (-10)/3 + 9/4) - (-3)/8 ÷ (8 - 51/8)`
`⇔ B = (-5)/6 ÷ (-13)/12 - (-3)/8 ÷ 13/8`
`⇔ B = (-5)/6 × (-12)/13 - (-3)/8 × 8/13`
`⇔ B = 10/13 - (-3)/13`
`⇔ B = (10 - (-3) )/13`
`⇔ B = 1`
Vậy `B=1`
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`C= (-3,2) × (-15)/64 + (0,8 - 14/5) ÷ 11/3`
`⇔ C = (-16)/5 × (-15)/64 + (-2) ×3/11`
`⇔ C = 3/4 + (-6)/11`
`⇔ C = 33/44 + (-24)/44`
`⇔ C = (33 + (-24) )/44`
`⇔ C = 9/44`
Vậy `C = 9/44`
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`D = 4/7 × 8/(-13) + 4/7 × (-2)/13 + 16/13 × (-4)/7`
`⇔ C = 4/7 × (-8)/13 + 3/7 × (-2)/13 + (-16)/13 × 4/7`
`⇔ C = 4/7 × [(-8)/13 + (-2)/13 + (-16)/13]`
`⇔ C = 4/7 × (-2)`
`⇔ C = (-8)/7`
Vậy `C = (-8)/7`
