\(\frac{2}{5}+\frac{1}{X}+\frac{1}{X}.2=0,1\)
\(\frac{2}{5}+\frac{1}{X}.3=0,1\)
\(\frac{1}{X}.3=0,1+\left(\frac{-2}{5}\right)\)
\(\frac{1}{X}.3=\frac{-3}{10}\)
\(\frac{1}{X}=\frac{-3}{10}:3\)
\(\frac{1}{X}=\frac{-1}{10}=\frac{1}{-10}\)
\(X=-10\)
Chúc bạn học giỏi!!!
(\(\frac{1}{1\cdot2}+\frac{1}{2\cdot3} +\frac{1}{3\cdot4}+\frac{1}{5\cdot6}\))*10-x=0
\(\frac{5}{6}+\frac{1}{3}\cdot x=\frac{8}{9}b,120+x\cdot2=7\cdot x+45\)
a)\(\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+\frac{1}{3\cdot4}+....+\frac{1}{2017\cdot2018}\) b)\(\left[x\cdot\frac{5}{3}-1\right]:9=3\frac{1}{2}:2,25\)
dấu chấm là dấu nhân nha :3
(\(\frac{1}{1\cdot2}\)+ \(\frac{1}{2\cdot3}+\frac{1}{3\cdot4}+\frac{1}{4\cdot5}+....+\frac{1}{9\cdot10}\)) *10 -x = 10
\(A=\frac{1\cdot2}{2\cdot2}\cdot\frac{2\cdot3}{3\cdot3}\cdot\frac{3\cdot4}{4\cdot4}\cdot\frac{4\cdot5}{5\cdot5}\cdot.................\cdot\frac{2012\cdot2013}{2013\cdot2013}\)với
\(B=\frac{2012\cdot2013-2012\cdot2012}{2012\cdot2011+2012\cdot2}\)
Trường THCS Lý Tự Trọng
Đề thi khảo sát chọn lớp dành cho học sinh thi vào lớp 6 môn toán
Bài 1 : Tính ( tính nhanh nếu có thể )
a) 1001 x 789 + 456 x 128 - 789 + 912 x 436
b) \(\left(2016\cdot2017+2017\cdot2018\right)\cdot\left(1+\frac{1}{2}:1\frac{1}{2}-1\frac{1}{3}\right)\)
c) \(5\frac{9}{10}:\frac{3}{2}-\left(2\frac{1}{3}\cdot4\frac{1}{2}-2\cdot2\frac{1}{3}\right):\frac{7}{4}\)
\(C=\frac{\left(100-\frac{2}{5}\right):\frac{1}{7}}{\left(6\frac{5}{9}-3\frac{1}{4}\right)\cdot2\frac{2}{17}}\)
\(\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+\frac{1}{3\cdot4}+\frac{1}{4\cdot5}+\frac{1}{5\cdot6}=\)
k mik mik k lại
1) Tính
a)\(\frac{13}{15}+\frac{13}{35}+\frac{13}{63}+\frac{13}{99}\)
b)\(\left(\frac{15}{1\cdot2\cdot3}+\frac{15}{2\cdot3\cdot4}+\frac{15}{3\cdot4\cdot5}+.....+\frac{15}{18\cdot19\cdot20}\right)\cdot x=1\)
