tính hợp lý a,A=6/2.5+6/5.8+6/8.11+….+6/29.32 b,B=15.9^5-4.9^6/9.9^4.2^5-3^9.8 09/10/2021 Bởi Katherine tính hợp lý a,A=6/2.5+6/5.8+6/8.11+….+6/29.32 b,B=15.9^5-4.9^6/9.9^4.2^5-3^9.8
Đáp án+Giải thích các bước giải: `a,A=6/(2.5)+6/(5.8)+6/(8.11)+….+6/(29.32)` `=2(3/(2.5)+3/(5.8)+3/(8.11)+…..+3/(29.32))` `=2(1/3-1/5+1/5-1/8+1/8-1/11+…..+1/29-1/32)` `=2(1/3-1/32)` `=2/3-1/16` `=29/48` `b,B=(15.9^5-4.9^6)/(9.9^4. 2^5-3^9. 8)` `=(9^5(15-4.9))/(9^5. 2^5+2^3. 9^4. 3)` `=(9^5(15-36))/(9^4. 2^3(2^2+3))` `=(9.(-21))/(8.7)` `=-27/8` Bình luận
Đáp án:
a,A=6/2.5+6/5.8+6/8.11+….+6/29.32
b,B=15.9^5-4.9^6/9.9^4.2^5-3^9.8
Đáp án+Giải thích các bước giải:
`a,A=6/(2.5)+6/(5.8)+6/(8.11)+….+6/(29.32)`
`=2(3/(2.5)+3/(5.8)+3/(8.11)+…..+3/(29.32))`
`=2(1/3-1/5+1/5-1/8+1/8-1/11+…..+1/29-1/32)`
`=2(1/3-1/32)`
`=2/3-1/16`
`=29/48`
`b,B=(15.9^5-4.9^6)/(9.9^4. 2^5-3^9. 8)`
`=(9^5(15-4.9))/(9^5. 2^5+2^3. 9^4. 3)`
`=(9^5(15-36))/(9^4. 2^3(2^2+3))`
`=(9.(-21))/(8.7)`
`=-27/8`