1+1+1+1+1+1+1+1+1+1+10=????
cac ban giup minh nha
{ 1 - 1/6 } x { 1 - 1/7 } x { 1- 1/8 } x { 1 - 1/9 } x { 1 - 10 }
=
=
=
mong cac ban giup minh nha
ai tra loi dung va nhanh thi minh se kb
\(\left(1-\frac{1}{6}\right)\times\left(1-\frac{1}{7}\right)\times\left(1-\frac{1}{8}\right)\times\left(1-\frac{1}{9}\right)\times\left(1-\frac{1}{10}\right)\)
\(=\frac{5}{6}\times\frac{6}{7}\times\frac{7}{8}\times\frac{8}{9}\times\frac{9}{10}\)
\(=\frac{5\times6\times7\times8\times9}{6\times7\times8\times9\times10}\)
\(=\frac{5}{10}\)
\(=\frac{1}{2}\)
Đường Quỳnh Giang 50 giây trước (19:06)
Thống kê hỏi đáp
Báo cáo sai phạm
(1−16 )×(1−17 )×(1−18 )×(1−19 )×(1−110 )
=56 ×67 ×78 ×89 ×910
=5×6×7×8×96×7×8×9×10
=510
(1-1/6)×(1-1/7)×(1-1/8)×(1-1/9)×(1-1/10)
=(6/6-1/6)×(7/7-1/7)×(8/8-1/8)×(9/9-1/9)×(10/10-1/10)
=5/6×6/7×7/8×8/9×9/10
=5/10
(Bạn gạch đi những số giống nhau nha)
Ví dụ:5/6×6/7=5/7(gạch bỏ số 6)
(x+1)^2=(x+1)^0
Cac ban giup minh nha
(x+1)^2=(x+1)^0=1
suy ra x+1 = -1 hoặc 1
suy ra x bằng -2 hoặc 0
(x+1)2=(x+1)0
(x+1)2=1
\(\Rightarrow\hept{\begin{cases}x+1=1\\x+1=-1\end{cases}}\)\(\Rightarrow\hept{\begin{cases}x=0\\x=-2\end{cases}}\)
(1/3+1/15+1/35+1/63)*x=1 va 1/3
giup minh vs tim x nha cac ban .thanks nhieu
Cái đề bài k hỉu j luôn sao lại bằng 1 và 1/3 !!
( 1/3 + 1/15 + 1/35 + 1/63 ) * x = 1 + 1/3
( 1/1x3 + 1/3x5 + 1/5x7 + 1/7x9 ) * x = 1 +1/3
1/2 x ( 2/1x3 + 2/3x5 + 2/5x7 + 2/7x9 ) * x = 1 + 1/3
1/2 x ( 1/1 - 1/3 + 1/3 - 1/5 + 1/5 - 1/7 + 1/7 - 1/9 ) * x = 1 + 1/3
1/2 x ( 1 - 1/9 ) * x = 4/3
1/2 x 8/9 * x = 4/3
4/9 * x = 4/3
x = 4/3 : 4/9
x = 9/3
x =3
Vậy x = 3
[x+80];5=40
[x-0,5];[1+1/2]=0,25
[1/1.2+1/2.3+1/3.4;x=1/2
25-[x+1,85];3=7
2/3;x/5=10/21
giup minh nha minh se tich cho cac ban
......................?
mik ko biết
mong bn thông cảm
nha ................
cac ban giup toi cau nay voi:
Thuc hien phep tinh(hop ly neu co the):
(10/99+11/199-12/299)x(1/2-1/3+-1/6)
mong cac ban giup minh nhanh voi a. Minh xin cam on
\(\left(\frac{10}{99}+\frac{11}{199}-\frac{12}{299}\right)\times\left(\frac{1}{2}-\frac{1}{3}+-\frac{1}{6}\right)\)
\(=\left(\frac{10}{99}+\frac{11}{199}-\frac{12}{299}\right)\times\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{6}\right)\)
\(=\left(\frac{10}{99}+\frac{11}{199}-\frac{12}{299}\right)\times\left(\frac{3}{6}-\frac{2}{6}-\frac{1}{6}\right)\)
\(=\left(\frac{10}{99}+\frac{11}{199}-\frac{12}{299}\right)\times0\)
\(=0\)
Chung minh rang :
S=1-1/2^2 -1/3^2 -1/4^2-1/5^2-......-1/10^2 >0
Cac ban giup minh giai nhe!
(x-3) chia het cho (x+1) ; (2x+5) chia het cho (x+1); (4x+1)chia het cho (2x+2)
CAC BAN GIUP MINH VOI NHA . MUM THANK CAC BAN TRC
cac ban giai giup minh bai nay voi , nhanh nha minh dang can gap
1/2+ 1/4 +1/8 + 1/16 + 1/32 + 1/64
tinh bang cach thuan tien nhat mha
\(=\frac{32+16+8+4+2+1}{64}=\frac{63}{64}\)
\(\frac{1}{1+\sqrt{2}}+\frac{1}{\sqrt{2}+\sqrt{3}}+....+\frac{1}{\sqrt{99}+\sqrt{100}}\)
giup minh voi
cam on nhieu
cac ban giai chi tiet giup minh nha
\(\frac{1}{\sqrt{a}+\sqrt{a+1}}=\frac{\sqrt{a+1}-\sqrt{a}}{\left(\sqrt{a}+\sqrt{a+1}\right)\left(\sqrt{a+1}-\sqrt{a}\right)}=\frac{\sqrt{a+1}-\sqrt{a}}{a+1-a}=\sqrt{a+1}-\sqrt{a}\Rightarrow\frac{1}{1+\sqrt{2}}+\frac{1}{\sqrt{2}+\sqrt{3}}+.......+\frac{1}{\sqrt{99}+\sqrt{100}}=-1+\sqrt{2}-\sqrt{2}+\sqrt{3}-......-\sqrt{99}+\sqrt{100}=10-1=9\)