15+16:5
So sánh :
a) (15^16 + 16^16)^15 và B= (15^15 + 16^15)^16
b) 5^255 và 2^572
5-5/3+5/9-5/27/8-8/3+8/9-8/27:15-15/11+15/121/16-16/11+16/121
5-5/3+5/9-5/27 15-15/11+15/121
____________ : ________________
8-8/3+8/9-8/27 16-16/11+16/121
a, -15/16 + 9/16 + 11/16
b, 2/3 . (1,4) + 1,6 . 2/3 - 1,2 . 2/3
c, 3 và 2/15. 3/5+ 3 và 2/15. 2/5- 31/15
a) \(\dfrac{-15+9+11}{16}=\dfrac{5}{16}\)
b) \(\dfrac{2}{3}\left(1,4+1,6-1,2\right)=\dfrac{2}{3}\times\dfrac{9}{5}=\dfrac{6}{5}\)
c) \(3\dfrac{2}{15}\left(\dfrac{3}{5}+\dfrac{2}{5}\right)-\dfrac{31}{15}=\dfrac{47}{15}-\dfrac{31}{15}=\dfrac{16}{15}\)
Tính nhẩm:
a)
15 − 6=..... 15 − 7=.....
15 − 8=..... 15 − 9=.....
16 − 7=..... 16 − 8=.....
16 − 9=..... 17 − 8=.....
17 − 9=..... 18 − 9=.....
b)
18 − 8 − 1=..... 18 − 9=.....
15 − 5 − 2=..... 15 − 7=.....
16 − 6 − 3=..... 16 − 9=.....
Phương pháp giải:
Trừ nhẩm các số rồi điền kết quả vào chỗ trống.
Lời giải chi tiết:
a)
15 − 6 = 9 15 − 7 = 8
15 − 8 = 7 15 − 9 = 6
16 − 7 = 9 16 − 8 = 8
16 − 9 = 7 17 − 8 = 9
17 − 9 = 8 18 − 9 = 9
b)
18 − 8 − 1 = 9 18 − 9 = 9
15 − 5 − 2 = 8 15 − 7 = 8
16 − 6 − 3 = 7 16 − 9 = 7
15 - 6 = 9,
15 - 8 =7,
15 - 7 = 8,
15 - 9 = 6
C=5-5/3+5/9.5+5/27 15-15/11+15/121
_________________ : __________________
8-8/3+8/9.8/27 16-16/11+16/121
\(\frac{5-\frac{5}{3}+\frac{5}{9}-\frac{5}{27}}{8-\frac{8}{3}+\frac{8}{9}-\frac{8}{27}}:\frac{15-\frac{15}{11}+\frac{15}{121}}{16-\frac{16}{11}+\frac{16}{121}}\)
\(\frac{5-\frac{5}{3}+\frac{5}{9}-\frac{5}{27}}{8-\frac{8}{3}+\frac{8}{9}-\frac{8}{27}}:\frac{15-\frac{15}{11}+\frac{15}{121}}{16-\frac{16}{11}+\frac{16}{121}}\)
\(=\frac{5\left(1-\frac{1}{3}+\frac{1}{9}-\frac{1}{27}\right)}{8\left(1-\frac{1}{3}+\frac{1}{9}-\frac{1}{27}\right)}:\frac{15\left(1-\frac{1}{11}+\frac{1}{121}\right)}{16\left(1-\frac{1}{11}+\frac{1}{121}\right)}\)
\(=\frac{5}{8}:\frac{15}{16}\)
\(=\frac{2}{3}\)
Viết số vào chỗ chấm cho thích hợp:
15−5=… 15−6=… |
15−7=… 15−8=… |
16−7=… 16−8=… |
16−9=… 18−9=… |
17−8=… 17−9=… |
|
15 – 5 = 10 15 – 6 = 9 |
15 – 7 = 8 15 – 8 = 7 |
16 – 7 = 9 16 – 8 = 8 |
16 – 9 = 7 18 – 9 = 9 |
17 – 8 = 9 17 – 9 = 8. |
|
Tính a,1/2+-3/4 b;2/5+-1/16+-9/5+-5/16 c,-2/13+8/15+10/20+15/13+-23/15 giải giúp m
\(a,\dfrac{1}{2}+\left(-\dfrac{3}{4}\right)=\dfrac{2}{4}+\left(-\dfrac{3}{4}\right)=-\dfrac{1}{4}\)
\(b,\dfrac{2}{5}+\left(-\dfrac{1}{16}\right)+\left(-\dfrac{9}{5}\right)+\left(-\dfrac{5}{16}\right)=\left(\dfrac{2}{5}-\dfrac{9}{5}\right)-\left(\dfrac{1}{16}+\dfrac{5}{16}\right)=\dfrac{-7}{5}-1=\dfrac{-12}{5}\)
\(c,\dfrac{-2}{13}+\dfrac{8}{15}+\dfrac{10}{20}+\dfrac{15}{13}+\left(-\dfrac{23}{15}\right)=\left(\dfrac{-2}{13}+\dfrac{15}{13}\right)+\left(\dfrac{8}{15}+\dfrac{-23}{15}\right)+\dfrac{1}{2}=1+\left(-1\right)+\dfrac{1}{2}=\dfrac{1}{2}\)
(Cho mik làm lại nha)
\(a,\dfrac{1}{2}+\left(-\dfrac{3}{4}\right)=\dfrac{2}{4}+\left(-\dfrac{3}{4}\right)=-\dfrac{1}{4}\)
\(a,\dfrac{2}{5}+\left(-\dfrac{1}{16}\right)+\left(-\dfrac{9}{5}\right)+\left(-\dfrac{5}{16}\right)=\left(\dfrac{2}{5}+\dfrac{-9}{5}\right)-\left(\dfrac{1}{16}+\dfrac{5}{16}\right)=\dfrac{-7}{5}-\dfrac{6}{16}=\dfrac{-71}{40}\)
\(c,\dfrac{-2}{13}+\dfrac{8}{15}+\dfrac{10}{20}+\dfrac{15}{13}+\left(-\dfrac{23}{15}\right)=\left(\dfrac{-2}{13}+\dfrac{15}{13}\right)+\left(\dfrac{8}{15}+\dfrac{-23}{15}\right)+\dfrac{1}{2}=1+\left(-1\right)+\dfrac{1}{2}=\dfrac{1}{2}\)
B=(13/5+7/16)-(15/16-6/15)
\(B=\left(\frac{13}{5}+\frac{7}{16}\right)-\left(\frac{15}{16}-\frac{6}{15}\right)\)
\(B=\left(\frac{13}{5}+\frac{6}{15}\right)-\left(\frac{7}{16}-\frac{15}{16}\right)\)
\(B=\left(\frac{39}{15}+\frac{6}{15}\right)-\frac{-8}{15}\)
\(B=\frac{45}{15}-\frac{-8}{15}\)
\(B=\frac{53}{15}\)