\(\frac{7}{13}\)x\(\frac{5}{6}\)x\(\frac{5}{13}\)
Tìm x, biết:
a) \(\left(\frac{4}{13}.\frac{6}{5}+\frac{4}{13}.\frac{2}{5}\right).\left(2x+1\right)^2=\frac{10}{13}\)
b) \(\frac{x-1}{x+5}=\frac{6}{7}\)
b)\(\frac{x-1}{x+5}=\frac{6}{7}\)
\(\Leftrightarrow7x-7=6x+30\)
\(\Leftrightarrow7x-6x=30+7\)
\(\Leftrightarrow x=37\)
Tìm x thuộc z biết :
X = \(\frac{\frac{3}{7}-\frac{3}{11}+\frac{3}{13}}{\frac{5}{7}-\frac{5}{11}+\frac{5}{13}}+\frac{\frac{1}{2}-\frac{1}{3}+\frac{1}{4}}{\frac{5}{4}-\frac{5}{5}+\frac{5}{6}}\)
giúp m nha !!! m tick
X=3/7:5/7-3/11:5/11+3/13:5/13
+
1/2:5/4-1/3+1/4:5/6
=3/5-3/5+3/5 + 2/5-1/3+3/10
=3/5 + 11/10
=17/10
B=\(\frac{5}{9}x\frac{7}{13}+\frac{5}{9}x\frac{9}{13}-\frac{5}{9}x\frac{3}{13}\)
B=\(\frac{5}{9}\)x{\(\frac{7}{13}\)+\(\frac{9}{13}\)-\(\frac{3}{13}\)}
B=\(\frac{5}{9}\)x 1
B=\(\frac{5}{9}\)
Vậy B=\(\frac{5}{9}\)
Chúc bạn hok tốt
B = \(\frac{5}{9}.\frac{7}{13}+\frac{5}{9}.\frac{9}{13}-\frac{5}{9}.\frac{3}{13}\)
Ta thấy có phân số \(\frac{5}{9}\) là thừa số chung
\(\Leftrightarrow\frac{5}{9}\left(\frac{7}{13}+\frac{9}{13}-\frac{3}{13}\right)=\frac{5}{9}\left(\frac{7+9+3}{13}\right)\)
\(=\frac{5}{9}.\frac{19}{13}\left(\frac{5.19}{9.13}\right)\)
\(=\frac{95}{117}\)
Tính giá trị các biểu thức sau một cách nhanh nhất:
a) 0.2 x 517 x 7 x 0.7 x 483 x 2
b) \(\frac{4}{9}+\frac{6}{11}+\frac{5}{9}+\frac{16}{11}+7\)
c) \(\frac{3}{5}+\frac{5}{1}+\frac{7}{13}+\frac{2}{5}+\frac{16}{11}+\frac{19}{13}\)
Tìm x biết \(\frac{-7}{13}\)x-5=\(6\frac{1}{3}\)+\(\frac{5}{13}\)x
Ta có: \(-\frac{7}{13}x-5=6\frac{1}{3}+\frac{5}{13}x\)
\(\Rightarrow-\frac{7}{13}x-\frac{5}{13}x=6\frac{1}{3}+5\)
\(\Rightarrow-\frac{12}{13}x=\frac{34}{3}\Rightarrow x=...\)
Tìm x biết −713 x-5=613 +513 x
\(\frac{-7}{13}x-\frac{5}{13}x=6\frac{1}{3}+5\)
\(x.\left(\frac{-7}{13}-\frac{5}{13}\right)=\frac{19}{3}+5\)
\(x.\frac{-12}{13}=\frac{34}{3}\)
\(x=\frac{34}{3}:\frac{-12}{13}\)
\(x=\frac{-221}{18}\)
Tính giá trị của các biểu thức sau bằng cách hợp lý nhất :
a)\(\left(4\frac{5}{37}-3\frac{4}{5}+8\frac{15}{29}\right)-\left(3\frac{5}{37}-6\frac{14}{29}\right)\)
b)\(60\frac{7}{13}x+50\frac{8}{13}x-11\frac{2}{13}x\)với \(x=-8\frac{7}{10}\)
B=81x[\(\frac{12-\frac{12}{7}-\frac{12}{289}-\frac{12}{85}}{4-\frac{4}{7}-\frac{4}{289}-\frac{4}{85}}:\frac{5+\frac{5}{13}+\frac{5}{169}+\frac{5}{91}}{6+\frac{5}{13}+\frac{5}{169}+\frac{5}{91}}\) ]x\(\frac{158158158}{711711711}\)
Tìm B
\(B=81\cdot\left(\frac{12-\frac{12}{7}-\frac{12}{289}-\frac{12}{85}}{4-\frac{4}{7}-\frac{4}{289}-\frac{4}{85}}:\frac{5+\frac{5}{13}+\frac{5}{169}+\frac{5}{91}}{6+\frac{5}{13}+\frac{5}{169}+\frac{5}{91}}\right)\cdot\frac{158158158}{711711711}\)
\(B=81\cdot\left(\frac{12\left(1-\frac{1}{7}-\frac{1}{289}-\frac{1}{85}\right)}{4\left(1-\frac{1}{7}-\frac{1}{289}-\frac{1}{85}\right)}:\frac{5\left(1+\frac{1}{13}+\frac{1}{169}+\frac{1}{91}\right)}{5\left(1+\frac{1}{13}+\frac{1}{169}+\frac{1}{91}\right)+1}\right)\cdot\frac{2}{9}\)
\(B=81\cdot\left(\frac{12}{4}:\frac{6470}{7653}\right)\cdot\frac{2}{9}\)
Xem lại đề bài bẹn owii -.-
\(\frac{13}{4}x-\frac{7}{6}x=\frac{5}{4}\)
\(\left(\frac{5}{7}-\frac{7}{9}+\frac{9}{11}+\frac{11}{13}+\frac{13}{15}\right).x=5-\frac{2}{7}-\frac{2}{9}-\frac{2}{11}-\frac{2}{13}\)