2b. Tính nhanh :
a) 4/3 + 3/5 + 7/3 + 2/5 + 1/3
b) 2/7 + -3/8 + 4/7 + 1/7 + -5/8
2b. Tính nhanh : a) 4/3 + 3/5 + 7/3 + 2/5 + 1/3 b) 2/7 + -3/8 + 4/7 + 1/7 + -5/8
By Josephine
By Josephine
2b. Tính nhanh :
a) 4/3 + 3/5 + 7/3 + 2/5 + 1/3
b) 2/7 + -3/8 + 4/7 + 1/7 + -5/8
Chúc bạn học tốt!!!
`a)` `4/3+3/5+7/3+2/5+1/3`
`=(4/3+7/3+1/3)+(3/5+2/5)`
`=12/3+5/5`
`=4+1`
`=5`
`b)` `2/7+(-3/8)+4/7+1/7+(-5/8)`
`=2/7-3/8+4/7+1/7-5/8`
`=(2/7+4/7+1/7)-(3/8+5/8)`
`=7/7-8/8`
`=1-1`
`=0`