Các câu hỏi tương tự
a, A= \(\frac{a^3.b}{4}\)+\(\frac{5c^2}{2}\)+ d với a= 2 , b= a , c= 6 , d =9
Bài 3 : Tính:
a, A = \(\frac{2}{5}+\frac{-1}{6}-\frac{3}{4}-\frac{-2}{3}\)
b, B = \(\frac{7}{10}-\frac{-3}{4}+\frac{-5}{6}-\frac{1}{5}+\frac{-2}{3}\)
c, C = \(\frac{\left(\frac{1}{2}-0,75\right)\times\left(0,2-\frac{2}{5}\right)}{\frac{5}{9}-1\frac{1}{12}}\)
d, D = \(\frac{\frac{2}{3}+\frac{2}{7}-\frac{1}{4}}{-1-\frac{3}{7}+\frac{3}{28}}\)
bài 1 : tìm x biếta, frac{2}{3}timesleft(x-frac{5}{6}right)+frac{1}{4}frac{22}{9}b, frac{2}{3}:frac{x}{5}frac{10}{21}c, frac{7}{3}:frac{x}{5}frac{14}{15}d, 1-left(5frac{4}{9}times x-7frac{7}{18}right):15frac{3}{4}0bài 2 : tính gtri bta,frac{8}{7}+frac{1}{5}timesfrac{10}{9}b, frac{3}{2}+left(frac{9}{2}+frac{2}{9}right)timesleft(frac{4}{3}-frac{5}{4}right)!_ove
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bài 1 : tìm x biết
a, \(\frac{2}{3}\times\left(x-\frac{5}{6}\right)+\frac{1}{4}=\frac{22}{9}\)
b, \(\frac{2}{3}:\frac{x}{5}=\frac{10}{21}\)
c, \(\frac{7}{3}:\frac{x}{5}=\frac{14}{15}\)
d, \(1-\left(5\frac{4}{9}\times x-7\frac{7}{18}\right):15\frac{3}{4}=0\)
bài 2 : tính gtri bt
a,\(\frac{8}{7}+\frac{1}{5}\times\frac{10}{9}\)
b, \(\frac{3}{2}+\left(\frac{9}{2}+\frac{2}{9}\right)\times\left(\frac{4}{3}-\frac{5}{4}\right)\)
!_ove
Tìm các số a,b,c,d sao cho:\(\frac{-7}{6}=\frac{a-2}{18}=\frac{-98}{3b+15}=\frac{14}{-5c+37}=\frac{d+1}{12}\)
tính giá trị biểu thứca, Afrac{-1}{2}-left[frac{-3}{5}right]+left[frac{-1}{9}right]+frac{1}{27}+frac{7}{18}+frac{4}{35}-left[-frac{2}{7}right]b, Bfrac{1}{3}-frac{3}{4}-left[frac{-3}{5}-frac{1}{57}+frac{1}{36}+frac{-1}{15}right]-frac{2}{9}c, Cleft[-frac{7}{15}right]timesfrac{5}{8}timesleft[frac{30}{-7}right]timesleft[-16right]timesleft[frac{-1}{1000}right]d, Dfrac{1}{2}timesfrac{-11}{19}-50%timesleft[-frac{1}{19}right]+frac{10}{19}timesfrac{1111}{2222}
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tính giá trị biểu thức
a, A=\(\frac{-1}{2}-\left[\frac{-3}{5}\right]+\left[\frac{-1}{9}\right]+\frac{1}{27}+\frac{7}{18}+\frac{4}{35}-\left[-\frac{2}{7}\right]\)
b, B=\(\frac{1}{3}-\frac{3}{4}-\left[\frac{-3}{5}-\frac{1}{57}+\frac{1}{36}+\frac{-1}{15}\right]-\frac{2}{9}\)
c, C=\(\left[-\frac{7}{15}\right]\times\frac{5}{8}\times\left[\frac{30}{-7}\right]\times\left[-16\right]\times\left[\frac{-1}{1000}\right]\)
d, D=\(\frac{1}{2}\times\frac{-11}{19}-50\%\times\left[-\frac{1}{19}\right]+\frac{10}{19}\times\frac{1111}{2222}\)
\(\frac{1}{2}+\frac{2}{3}+\frac{3}{4}+\frac{4}{5}+\frac{5}{6}< 4\)4 (Chứng tỏ)
\(\frac{a}{a+b+c}+\frac{b}{b+c+a}+\frac{c}{c+d+a}+\frac{d}{d+a+b}\)
(Chứng tỏ)
\(\frac{3}{8}\) viết 2 phân số thành tổng 2 phân số có tử là 1
a, Đặt \(\frac{a}{b}=\frac{c}{d}=k\Rightarrow a=b.k,c=d.k\)
+) \(\frac{5a+3b}{5a-3b}=\frac{5.b.k+3.b}{5.b.k-3.b}=\frac{b.\left(5k+3\right)}{b.\left(5k-3\right)}=\frac{5k+3}{5k-3}\left(1\right)\)
+) \(\frac{5c+3d}{5c-3d}=\frac{5.d.k+3.d}{5.d.k-3.d}=\frac{d.\left(5k+3\right)}{d.\left(5k-3\right)}=\frac{5k+3}{5k-3}\left(2\right)\)
Từ (1) và(2) => ĐPCM
bài 2: tính giá trị các bt sau:a) Nfrac{13}{12}times a-frac{1}{4}times b-frac{13}{12}times bvới a-bfrac{3}{8}b)Cfrac{3}{16}times a-frac{3}{8}times b+frac{3}{16}times cvới a+c2b+1 bài 3:A 1+frac{1}{2}+frac{1}{3}+frac{1}{4}+.....+frac{1}{63}CMR:A6M 1+frac{1}{2}+frac{1}{3}+frac{1}{4}+....+frac{1}{199}+frac{1}{200}CMR:M2frac{1}{12}Bfrac{1}{^{2^2}}+frac{1}{3^2}+frac{1}{4^2}+....+frac{1}{19^2}+frac{1}{20^2}CMR:Bfrac{3}{4}Cfrac{1}{2^2}+frac{1}{3^2}+frac{1}{4^2}+.....+frac{1}{100^2}CMR:C1
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bài 2: tính giá trị các bt sau:
a) N=\(\frac{13}{12}\times a-\frac{1}{4}\times b-\frac{13}{12}\times b\)với a-b=\(\frac{3}{8}\)
b)C=\(\frac{3}{16}\times a-\frac{3}{8}\times b+\frac{3}{16}\times c\)với a+c=2b+1
bài 3:
A= 1+\(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+.....+\frac{1}{63}\)
CMR:A<6
M= 1+\(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+....+\frac{1}{199}+\frac{1}{200}\)
CMR:M>\(2\frac{1}{12}\)
B=\(\frac{1}{^{2^2}}+\frac{1}{3^2}+\frac{1}{4^2}+....+\frac{1}{19^2}+\frac{1}{20^2}\)
CMR:B<\(\frac{3}{4}\)
C\(=\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+.....+\frac{1}{100^2}\)
CMR:C<1
A left(frac{1}{2}+frac{1}{4}+frac{1}{8}-1right)timesleft(1-frac{8}{1}-frac{4}{1}-frac{2}{1}right)B frac{frac{3}{1}-frac{6}{3}-frac{9}{6}-frac{369}{1}}{frac{1}{3}+frac{3}{6}+frac{6}{9}-frac{1}{963}}C frac{1}{1}-frac{1}{2}+frac{3}{1}-frac{1}{4}+frac{5}{1}-frac{1}{6}+frac{7}{1}-frac{1}{8}+frac{9}{1}-frac{1}{10}so sánh các số trên ( A , B , C )
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A = \(\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}-1\right)\times\left(1-\frac{8}{1}-\frac{4}{1}-\frac{2}{1}\right)\)
B = \(\frac{\frac{3}{1}-\frac{6}{3}-\frac{9}{6}-\frac{369}{1}}{\frac{1}{3}+\frac{3}{6}+\frac{6}{9}-\frac{1}{963}}\)
C = \(\frac{1}{1}-\frac{1}{2}+\frac{3}{1}-\frac{1}{4}+\frac{5}{1}-\frac{1}{6}+\frac{7}{1}-\frac{1}{8}+\frac{9}{1}-\frac{1}{10}\)
so sánh các số trên ( A , B , C )