tính :
\(\frac{27.18+27.103-120.27}{15.33+33.12}\)
ai đúng và nhanh nhất tớ tick cho
. là dấu nhân
N=\(\frac{27.18+27.103-120.27}{15.33+33.12}\).tính nhanh
thu gọn c=27.18+27.103-120.27\15.33+33.12
\(\frac{27.18+27.103-120.27}{15.33+33.12}\)
\(\left|x-\frac{1}{3}\right|=\frac{5}{6}\)
\(\frac{27\cdot18+27\cdot103-27\cdot120}{15\cdot33+12\cdot33}=\frac{27\left(18+103-120\right)}{33\left(15+12\right)}\)\(=\frac{27\cdot1}{33\cdot27}=\frac{1}{33}\)
\(\Leftrightarrow x-\frac{1}{3}=\left(+-\right)\frac{5}{6}\)
nếu \(x-\frac{1}{3}=\frac{5}{6}\) nếu \(x-\frac{1}{3}=-\frac{5}{6}\)
\(\Leftrightarrow x=\frac{5}{6}+\frac{1}{3}\) \(\Leftrightarrow x=-\frac{5}{6}+\frac{1}{3}\)
\(\Leftrightarrow x=\frac{7}{6}\) \(\Leftrightarrow x=-\frac{1}{2}\)
Vậy ....
nhớ k mk nha bạn , mk nhanh nhất
thanks
\(\frac{27.18+27.103-120.27}{15.33+33.12}\)
\(=\)\(\frac{27.\left(18+103-120\right)}{33.\left(15+12\right)}\)
\(=\)\(\frac{27.1}{33.27}\)
\(=\)\(\frac{1}{33}\)
\(|x-\frac{1}{3}|=\frac{5}{6}\)
\(\Rightarrow\)\(\orbr{\begin{cases}x-\frac{1}{3}=\frac{5}{6}\\x-\frac{1}{3}=-\frac{5}{6}\end{cases}}\)
\(\Rightarrow\)\(\orbr{\begin{cases}x=\frac{5}{6}+\frac{1}{3}\\x=-\frac{5}{6}+\frac{1}{3}\end{cases}}\)
\(\Rightarrow\)\(\orbr{\begin{cases}x=\frac{7}{6}\\x=-\frac{1}{2}\end{cases}}\)
Vậy \(x=\frac{7}{6};-\frac{1}{2}\)
Bài 1: Tính gái trị biểu thức sau:
1) \(\dfrac{-5}{2}:\left(\dfrac{3}{4}-\dfrac{1}{2}\right)\)
2) \(\dfrac{298}{719}:\left(\dfrac{1}{4}+\dfrac{1}{12}-\dfrac{1}{3}\right)-\dfrac{2011}{2012}\)
3) \(\dfrac{27.18+27.103-120.27}{15.33+33.12}\)
1)\(\dfrac{-5}{2}:\dfrac{1}{4}\) = \(\dfrac{-5}{2}\) x \(\dfrac{4}{1}\) = \(\dfrac{-20}{2}\)
1) \(\dfrac{-5}{2}:\left(\dfrac{3}{4}-\dfrac{1}{2}\right)\) \(=\dfrac{-5}{2}:\dfrac{1}{4}=-10\)
tính giá trị biểu thức
a,\(\dfrac{298}{719}:(\dfrac{1}{4}+\dfrac{1}{12}+\dfrac{1}{3})-\dfrac{2011}{2012}\)
b,\(\dfrac{27.18+27.103-120.27}{15.33+33.12}\)
a) \(\dfrac{298}{719}:\left(\dfrac{1}{4}+\dfrac{1}{12}+\dfrac{1}{3}\right)-\dfrac{2011}{2012}=\dfrac{298}{719}:\left(\dfrac{3}{12}+\dfrac{1}{12}+\dfrac{4}{12}\right)-\dfrac{2011}{2012}=\dfrac{298}{719}:\left(\dfrac{3+1+4}{12}\right)-\dfrac{2011}{2012}=\dfrac{298}{719}:\dfrac{2}{3}-\dfrac{2011}{2012}=\dfrac{298}{719}\cdot\dfrac{3}{2}-\dfrac{2011}{2012}=\dfrac{149.3}{719.1}-\dfrac{2011}{2012}=\dfrac{447}{719}-\dfrac{2011}{2012}=\dfrac{889364}{1446628}-\dfrac{1445909}{1446628}=\dfrac{889364-1445909}{1446628}=-\dfrac{556545}{1446628}.\)b)\(\dfrac{27\cdot18+27+103-120\cdot27}{15\cdot33+33\cdot12}=\dfrac{27\left(18+103-120\right)}{33\left(15+12\right)}=\dfrac{27\cdot1}{33\cdot27}=\dfrac{1\cdot1}{33\cdot1}=\dfrac{1}{33}\)
Câu hỏi : Tính hợp lí
\(\frac{27.18+27.103-27.102}{15.33+33.12}\)
Câu hỏi : Tính hợp lí
27.18+27.103−27.10215.33+33.1227.18+27.103−27.10215.33+33.12
giúp mình giải mấy bài này nhé:
a) \(\frac{298}{719}:\left(\frac{1}{4}+\frac{1}{12}-\frac{1}{3}\right)-\frac{2011}{2012}\) b)\(\frac{27.18+27.103-120.27}{15.33+33.12}\)
2. rút gọn : B=\(\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right).\left(1-\frac{1}{4}\right)...\left(1-\frac{1}{20}\right)\)
\(\frac{27.\left(18+103-120\right)}{33.\left(15+12\right)}\)=\(\frac{27.1}{33.27}\)=\(\frac{1}{33}\)
mik dang ban moi giai duoc mot bai ha, sorry
\(\frac{27\cdot18\cdot27\cdot103-102\cdot27}{15\cdot33+33\cdot12}\)
=\(\frac{27\cdot\left(18+103-102\right)}{33\cdot\left(15+12\right)}\)
=\(\frac{27\cdot19}{33\cdot27}\)
=\(\frac{19}{33}\)
1.tính các biểu thức sau bằng một cách hợp lí
a.\(\frac{108}{119}.\frac{107}{211}+\frac{108}{119}.\frac{104}{211}\)
b.\(\frac{15}{19}.\frac{27}{33}+\frac{15}{19}.\frac{19}{33}-\frac{15}{19}.\frac{13}{33}\)
c.\(\frac{-4}{5}.\frac{13}{10}+\frac{-4}{5}.\frac{7}{10}-\frac{-4}{5}\)
d.\(\frac{\frac{-2}{7}-\frac{-2}{15}+\frac{-2}{39}}{\frac{5}{7}-\frac{5}{15}+\frac{5}{39}}\)
e.\(\frac{3}{5}.\frac{15}{7}-\frac{15}{7}.\frac{8}{5}\)
f.\(\frac{2}{3}+\frac{1}{3}.\left(\frac{-4}{9}+\frac{5}{6}\right):\frac{7}{12}\)
h.\(\frac{\frac{3}{5}+\frac{3}{7}-\frac{3}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{11}}\)
g.\(\frac{3}{-4}+\frac{2}{7}+\frac{-1}{4}+\frac{5}{7}+\frac{21}{22}.\frac{66}{7}\)
k.\(\frac{27.18+27.103-120.27}{15.33+33.12}\)
l.\(\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{9}-\frac{4}{11}}\)
\(a.\frac{108}{119}.\frac{107}{211}+\frac{108}{119}.\frac{104}{211}=\frac{108}{119}.\left(\frac{107}{211}+\frac{104}{211}\right)=\frac{108}{119}.1=108\)