15 x 16 x 17 x ... x 2016 x 2017
16 x 17 x 18 x ...... x 2016 x 2017
tìm x biết
\(\frac{x+18}{2018}+\frac{x+17}{2017}+\frac{x+16}{2016}\)=3
\(\frac{x+18}{2018}+\frac{x+17}{2017}+\frac{x+16}{2016}=3\)
\(\Rightarrow\frac{x+18}{2018}-1+\frac{x+17}{2017}-1+\frac{x+16}{2016}-1=3-3\)
\(\Rightarrow\frac{x+18-2018}{2018}+\frac{x+17-2017}{2017}+\frac{x+16-2016}{2016}=0\)
\(\Rightarrow\frac{x-2000}{2018}+\frac{x-2000}{2017}+\frac{x-2000}{2016}=0\)
\(\Rightarrow\left(x-2000\right)\left(\frac{1}{2018}+\frac{1}{2017}+\frac{1}{2016}\right)=0\)
Vì \(\frac{1}{2018}+\frac{1}{2017}+\frac{1}{2016}\ne0\)
=> x - 2000 = 0
=> x = 2000
Ta có :
\(\frac{x+18}{2018}+\frac{x+17}{2017}+\frac{x+16}{2016}=3\)
\(\Leftrightarrow\)\(\left(\frac{x+18}{2018}-1\right)+\left(\frac{x+17}{2017}-1\right)+\left(\frac{x+16}{2016}-1\right)=3-3\) ( trừ hai vế cho 3 )
\(\Leftrightarrow\)\(\frac{x-2000}{2018}+\frac{x-2000}{2017}+\frac{x-2000}{2016}=0\)
\(\Leftrightarrow\)\(\left(x-2000\right)\left(\frac{1}{2018}+\frac{1}{2017}+\frac{1}{2016}\right)=0\)
Vì \(\frac{1}{2018}+\frac{1}{2017}+\frac{1}{2016}\ne0\)
Nên \(x-2000=0\)
\(\Rightarrow\)\(x=2000\)
Vậy \(x=2000\)
Chúc bạn học tốt ~
\(1\dfrac{1}{15}\) x \(1\dfrac{1}{16}\) x \(1\dfrac{1}{17}\) x ..... x \(1\dfrac{1}{2016}\) x \(1\dfrac{1}{2017}\)
\(A=1\dfrac{1}{15}.1\dfrac{1}{16}.1\dfrac{1}{17}......1\dfrac{1}{2016}.1\dfrac{1}{2017}\)
\(A=\dfrac{16}{15}.\dfrac{17}{16}.\dfrac{18}{17}......\dfrac{2017}{2016}.\dfrac{2018}{2017}\)
\(A=\dfrac{16.17.18......2017.2018}{15.16.17......2016.2017}\)
\(A=\dfrac{2018}{15}\)
Tìm số tự nhiên x và y biết
a) 234:2(3.x-12)-12+17=17.5-5
b) (2.x+15):7+26-20=11
c) 225:(3.x-12)-12+17=17.5=5
d) (3.x+6).(15-3.x)=0
e) (3.x-15).(40-8.x)+2017=2017
f) {(x.14-2015).5+2016}.2017={(2100-2015).5+2016}.2017
g) (2.x+1).(y-2)=6
h) (3y+1).(x-2)=9
Ai giúp được câu nào thì giúp em với ạ :(((Em đang cần gấp
1 x \(\frac{1}{15}\) x 1\(\frac{1}{16}\) x 1\(\frac{1}{17}\) x............x 1\(\frac{1}{2016}\) x 1\(\frac{1}{2017}\)
Ta có: \(1\times\frac{1}{15}\times1\frac{1}{16}\times1\frac{1}{17}\times......\times1\frac{1}{2016}\times1\frac{1}{2017}\)
\(=\frac{1}{15}\times\frac{17}{16}\times\frac{18}{17}\times......\times\frac{2017}{2016}\times\frac{2018}{2017}\)
\(=\frac{1}{15}\times\frac{2018}{16}\)
\(=\frac{1009}{8\times15}\)
\(=\frac{1009}{120}\)
Mình nghĩ đề bài của bạn bị nhầm ở chỗ \(1\frac{1}{15}\)thành \(1\times\frac{1}{15}\)
Nhưng không sao bạn ạ
Vẫn giải được
\(1\frac{1}{15}\times1\frac{1}{16}\times.....\times1\frac{1}{2017}\)(lỗi đề sao bạn)
\(=\frac{16}{15}\times\frac{17}{16}\times.....\times\frac{2018}{2017}\)
\(=\frac{16\times17\times.....\times2018}{15\times16\times.....\times2017}\)
\(=\frac{2018}{15}\)
tìm giá trị nhỏ nhất của biểu thức P = (x+2y)2016+5|x+5|2017+16/(x+2y)2016+5|x+5|+15
nhanh nhanh nha nha tui đâng cần gấp đó nha nha nhanh nha
a)\(\frac{x+1}{5}+\frac{x+1}{6}+\frac{x+1}{7}=\frac{x+1}{8}+\frac{x+1}{9}\)
b)\(\frac{x+6}{2015}+\frac{x+5}{2016}+\frac{x+4}{2017}=\frac{x+3}{2018}+\frac{x+2}{2019}+\frac{x+1}{2010}\)
c)\(\frac{x+6}{2016}+\frac{x+7}{2017}+\frac{x+8}{2018}=\frac{x+9}{2019}+\frac{x+10}{2020}+1\)
d)\(\frac{x-90}{10}+\frac{x-76}{12}+\frac{x-58}{14}+\frac{x-36}{16}+\frac{x-15}{17}=15\)
ai xong nhanh nhất và đúng em xin gửi 2 SP ạ
a) \(\frac{x+1}{5}+\frac{x+1}{6}+\frac{x+1}{7}=\frac{x+1}{8}+\frac{x+1}{9}\)
\(\Leftrightarrow\frac{x+1}{5}+\frac{x+1}{6}+\frac{x+1}{7}-\frac{x+1}{8}-\frac{x+1}{9}=0\)
\(\Leftrightarrow\left(x+1\right).\left(\frac{1}{5}+\frac{1}{6}+\frac{1}{7}-\frac{1}{8}-\frac{1}{9}\right)=0\)
\(\Leftrightarrow x+1=0\)
\(\Leftrightarrow x=0-1\)
\(\Rightarrow x=-1\)
Vậy \(x=-1.\)
Mình chỉ làm câu a) thôi nhé.
Chúc bạn học tốt!
Lê Thị Thục HiềnTrần Thanh PhươngVũ Minh Tuấn?Amanda?Nguyễn Việt LâmHISINOMA KINIMADONguyễn Huy TúAkai Haruma
\(1\frac{1}{15}\)x \(1\frac{1}{16}\)x \(1\frac{1}{17}\)x .......... x \(1\frac{1}{2016}\)x \(1\frac{1}{2017}\)
\(1\frac{1}{15}\cdot1\frac{1}{16}\cdot1\frac{1}{17}\cdot...\cdot1\frac{1}{2016}\cdot1\frac{1}{2017}\)
\(=\frac{16^{\left(1\right)}}{15}\cdot\frac{17^{\left(1\right)}}{16^{\left(1\right)}}\cdot\frac{18^{\left(1\right)}}{17^{\left(1\right)}}\cdot...\cdot\frac{2017^{\left(1\right)}}{2016^{\left(1\right)}}\cdot\frac{2018}{2017^{\left(1\right)}}\)
\(=\frac{1}{15}\cdot2018\)
\(=\frac{2018}{15}=134\frac{8}{15}\)
Tính nhanh:
1 x \(\frac{1}{15}\)x 1\(\frac{1}{16}\)x \(1\frac{1}{17}\)x........x \(1\frac{1}{2016}\)x \(1\frac{1}{2017}\)
Tính nhanh giúp mình nha!
\(1\cdot\frac{1}{15}\cdot1\frac{1}{16}\cdot1\frac{1}{17}\cdot....\cdot1\frac{1}{2016}\cdot1\frac{1}{2017}\)
\(=\frac{1}{15}\cdot\frac{17}{16}\cdot\frac{18}{17}\cdot....\cdot\frac{2017}{2016}\cdot\frac{2018}{2017}\)
\(=\frac{1}{15}\cdot\frac{1}{16}\cdot2018\)
Dấu "." là dấu nhân nhé bn! phần còn lại bn làm tiếp nha