Đáp án:
Giải thích các bước giải:
`3/4+ 2/5 + 1/4 +3/5`
`=(3/4+ 1/4) + (2/5+ 3/5)`
`= 1+1`
`=2`
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`4/5× 3/7+ 4/5× 4/7`
`=4/5×(3/7+4/7)`
`= 4/5× 1`
`= 4/5`
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`2/3 × 3/4 × 4/5 × 5/6`
`= 2×3×4×5/3×4×5×6`
`= 2×3×4×5/3×4×5×2×3`
`=1/3`
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`2/5× 7/4 - 2/5 × 3/7`
`= 2/5×(7/4-3/7)`
`=2/5 ×37/8`
`=37/70`
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`4/5- 2/3+ 1/5 -1/3`
`= (4/5+ 1/5)- (2/3- 1/3)`
`= 1-1`
`=0`
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`13/4 × 2/3 × 4/13 × 3/2`
`=13×2×4×3/4×3×13×2`
`=1`
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`75/100 + 18/21+ 19/32 + 1/4 + 3/21 +13/32`
`=75/100+(18/21+3/21)+(19/32+13/32)`
`=75/100 + 1+1`
`= 75/100+ 100/100 +100/100`
`=275/100`
`=11/4`
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`2/5 + 6/9 + 3/4+ 3/5 + 1/3 + 1/4`
`=2/5 +2/3 + 3/4 + 3/5 + 1/3 +1/4`
`=(2/5 + 3/5) +(2/3+ 1/3)+ (3/4+ 1/4)`
`=1+1+1`
`=3`