(1/3)^2x1/3x9^2
1\2x1\3+2\3+1\2
\(\dfrac{1}{2}\times\dfrac{1}{3}+\dfrac{2}{3}+\dfrac{1}{2}\)
\(=\dfrac{1}{6}+\dfrac{2}{3}+\dfrac{1}{2}\)
\(=\dfrac{1}{6}+\dfrac{4}{6}+\dfrac{3}{6}\)
\(=\dfrac{8}{6}=\dfrac{4}{3}\)
X-1/3=2/3x9/14+3/7
tìm X ạ giúp mik vs mai mik đi học r:(
\(x-\dfrac{1}{3}=\dfrac{2}{3}.\dfrac{9}{14}+\dfrac{3}{7}\)
\(x-\dfrac{1}{3}=\dfrac{1}{7}+\dfrac{3}{7}\)
\(x-\dfrac{1}{3}=\dfrac{4}{7}\)
\(x=\dfrac{19}{21}\)
a.1/5x1/2:3/10
b.1/2x1/3:1/4
`1/5xx1/2:3/10`
`=1/10xx10/3`
`=1/3`
`1/2xx1/3:1/4`
`=1/6xx4/1`
`=2/3`
a. \(\dfrac{1}{5}\times\dfrac{1}{2}:\dfrac{3}{10}=\dfrac{1}{10}:\dfrac{3}{10}=\dfrac{1}{10}\times\dfrac{10}{3}=\dfrac{10}{30}=\dfrac{1}{3}\)
b. \(\dfrac{1}{2}\times\dfrac{1}{3}:\dfrac{1}{4}=\dfrac{1}{6}:\dfrac{1}{4}=\dfrac{1}{6}\times\dfrac{4}{1}=\dfrac{4}{6}=\dfrac{2}{3}\)
a) \(\dfrac{1}{5}\times\dfrac{1}{2}:\dfrac{3}{10}=\dfrac{1}{5}\times\dfrac{1}{2}\times\dfrac{10}{3}=\dfrac{1\times1\times10}{5\times2\times3}=\dfrac{10}{30}=\dfrac{1}{3}\)
b) \(\dfrac{1}{2}\times\dfrac{1}{3}:\dfrac{1}{4}=\dfrac{1}{2}\times\dfrac{1}{3}\times4=\dfrac{1\times1\times4}{2\times3}=\dfrac{4}{6}=\dfrac{2}{3}\)
tinh nhanh (5/12+1/2x1/3):(2x1/3-1x5/12)
\(\left(\frac{5}{12}+\frac{1}{2}.\frac{1}{3}\right):\left(2.\frac{1}{3}-1.\frac{5}{12}\right)\)
\(=\left(\frac{5}{12}+\frac{1}{6}\right):\left(\frac{2}{3}-\frac{5}{12}\right)\)
\(=\frac{7}{12}:\frac{1}{4}\)
\(=\frac{7}{3}\)
_Chúc bạn học tốt_
tinh nhanh (5/12+1/2x1/3):(2x1/3-1x1/12) giup mình
Đề bài
= ( 5/12 + 1/6 ) : ( 2/3 - 1/12 )
= ( 5/12 + 2/12 ) : ( 8/12 - 1/12 )
= 7/12 : 7/12
= 1
K Trắng nha .
tinh nhanh (5/12+1/2x1/3):(2x1/3-1x1/12) giup mình
\(\left(\frac{5}{12}+\frac{1}{2}\times\frac{1}{3}\right):\left(2\times\frac{1}{3}-1\times\frac{1}{12}\right)\)
\(=\left(\frac{5}{12}+\frac{1}{6}\right):\left(\frac{2}{3}-\frac{1}{12}\right)\)
\(=\frac{7}{12}:\frac{7}{12}\)
\(=1\)
k bk tính nhanh!
Chúng minh rằng: 2x1-1/2! + 3x2-1/3! + ..... + 99x100 -1/100! < 2
Uk, Long cứ đợi ng ta trả lời xong long làm giống là đc ý mà!
Xin lỗi Long vì có hơi bực nên mới nói vậy, mong bn bỏ qua
1/2x1+1/3x(1+2)+1/4x(1+2+3)+...+1/100x(1+2+3+...+99+100)
Giup minh voi
a)4/5-(1/5+1/3)
b)12/7-(3/14-1)
c)11/2-9(7/5-1/2)
d)3x9(4/7+3/5)
e) (1/3-1/5):2
f)123/34:1/17-21/34:1/17
a) \(\dfrac{4}{5}-\left(\dfrac{1}{5}+\dfrac{1}{3}\right)=\dfrac{4}{5}-\left(\dfrac{3}{15}+\dfrac{5}{15}\right)=\dfrac{4}{5}-\dfrac{8}{15}=\dfrac{12}{15}-\dfrac{8}{15}=\dfrac{4}{15}\)
b) \(\dfrac{12}{7}-\left(\dfrac{3}{14}-1\right)=\dfrac{12}{7}-\left(-\dfrac{11}{14}\right)=\dfrac{12}{7}+\dfrac{11}{14}=\dfrac{5}{2}\)
c) \(\dfrac{11}{2}-9\cdot\left(\dfrac{7}{5}-\dfrac{1}{2}\right)=\dfrac{11}{2}-9\cdot\dfrac{9}{10}=\dfrac{11}{2}-\dfrac{81}{10}=\dfrac{55}{10}-\dfrac{81}{10}=-\dfrac{13}{5}\)
d) \(3\times9\left(\dfrac{4}{7}+\dfrac{3}{5}\right)=27\times\dfrac{41}{35}=\dfrac{1107}{35}\)
e) \(\left(\dfrac{1}{3}-\dfrac{1}{5}\right):2=\left(\dfrac{5}{15}-\dfrac{3}{15}\right):2=\dfrac{2}{15}:2=\dfrac{2}{15}\times\dfrac{1}{2}=\dfrac{1}{15}\)
f) \(\dfrac{123}{34}:\dfrac{1}{17}-\dfrac{21}{34}:\dfrac{1}{17}=\left(\dfrac{123}{34}-\dfrac{21}{34}\right):\dfrac{1}{17}=3:\dfrac{1}{17}=3\times17=51\)