\(\frac{9}{27}+\frac{8}{24}+\frac{18}{27}-\frac{-16}{24}+\frac{2}{3}\)
Rut gon: \(A=\frac{9+\frac{9}{11}+\frac{18}{23}-\frac{27}{27}}{8+\frac{8}{11}+\frac{16}{23}-\frac{24}{37}}-\frac{2+\frac{16}{29}-\frac{24}{13}-\frac{32}{11}}{3+\frac{24}{29}-\frac{36}{13}-\frac{48}{11}}\)
\(\frac{9+\frac{9}{11}+\frac{18}{23}-\frac{27}{37}}{8+\frac{8}{11}+\frac{16}{23}-\frac{24}{37}}-\frac{2+\frac{16}{29}-\frac{24}{13}-\frac{32}{11}}{3+\frac{24}{29}-\frac{36}{13}-\frac{48}{11}}\)
Thuc hien phep tinh
Đặt \(A=\frac{9+\frac{9}{11}+\frac{18}{23}-\frac{27}{37}}{8+\frac{8}{11}+\frac{16}{23}-\frac{24}{37}}-\frac{2+\frac{16}{29}-\frac{24}{13}-\frac{32}{11}}{3+\frac{24}{29}-\frac{36}{13}-\frac{48}{11}}\)\(=\frac{9\left(1+\frac{1}{11}+\frac{2}{23}-\frac{3}{37}\right)}{8\left(1+\frac{1}{11}+\frac{2}{23}-\frac{3}{37}\right)}-\frac{2\left(1+\frac{8}{29}-\frac{12}{13}-\frac{16}{11}\right)}{3\left(1+\frac{8}{29}-\frac{12}{13}-\frac{16}{11}\right)}\)
\(=\frac{9}{8}-\frac{2}{3}\)(do \(1+\frac{1}{11}+\frac{2}{23}-\frac{3}{37};1+\frac{8}{29}-\frac{12}{13}-\frac{16}{11}\ne0\))
\(=\frac{27}{24}-\frac{16}{24}=\frac{11}{24}.\)
Vậy A = \(\frac{11}{24}.\)
Bài 1:
a, \(\frac{2}{5}.\frac{1}{3}-\frac{2}{15}:\frac{1}{5} +\frac{3}{5}.\frac{1}{3}\)
b, \(\frac{9}{27}+\frac{8}{24}+\frac{18}{27}-\frac{-16}{24}+\frac{2}{3}\)
c,\(\left(4-\frac{5}{12}\right):2+\frac{5}{24}\)
a) -1/3
b)8/3
c)2
k cho mk nha mk cảm ơn nhiều
bài 1:thực hiện phép tính :
a)\(\frac{3}{7}+\frac{5}{13}+\frac{4}{13}\)
b)\(\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)
c)\(\frac{2}{5}.\frac{1}{3}-\frac{2}{15}:\frac{1}{5}+\frac{3}{5}.\frac{1}{3}\)
d)\(\left(4-\frac{5}{12}\right):2+\frac{5}{24}\)
e)\(\frac{7}{19}.\frac{8}{11}+\frac{3}{11}.\frac{7}{19}+\frac{-1}{19}\)
f)\(\frac{9}{27}+\frac{8}{24}+\frac{18}{27}-\frac{-16}{24}+\frac{2}{3}\)
g)\(\frac{-5}{21}+\frac{-2}{21}+\frac{8}{24}\)
h)\(\frac{-5}{9}+\frac{8}{15}+\frac{-2}{11}+\frac{4}{-9}+\frac{7}{15}\)
i)\(\frac{7}{25}.\frac{39}{-14}.\frac{50}{78}\)
m.n làm nhanh cho mình nhé, chiều mình phải nộp rồi! cảm ơn m.n!
\(\frac37+\frac{5}{13}+\frac{4}{13}\)
=\(\frac37+\left(\frac{5}{13}+\frac{4}{13}\right)\)
=\(\frac37+\frac{9}{13}\)
=\(\frac{39}{91}+\frac{63}{91}\)
=\(\frac{102}{91}\)
\(\left(\frac38+\frac{-3}{4}+\frac{7}{12}\right):\frac56+\frac12\)
=\(\left(\frac{9}{24}+\frac{-18}{24}+\frac{7}{24}\right)\times\frac65+\frac12\)
=\(\frac{5}{24}\times\frac65+\frac12\)
=\(\frac14+\frac12\)
=\(\frac14+\frac24\)
=\(\frac34\)
\(\frac25\times\frac13-\frac{2}{15}:\frac15+\frac35\times\frac13\)
=\(\frac{2}{15}-\frac{2}{15}.5+\frac15\)
=\(\frac{2}{15}\times\left(1-5\right)+\frac15\)
=\(\frac{2}{15}\times\left(-4\right)+\frac15\)
=\(-\frac{8}{15}+\frac15\)
=\(-\frac{8}{15}+\frac{3}{15}\)
=\(-\frac{5}{15}=-\frac13\)
\(\frac{6+a}{9-a^2}+...=\frac{6}{9-a^2}+...+\frac{a^2}{9a-a^3}\ge\frac{54}{27-a^2-b^2-c^2}+\frac{\left(a+b+c\right)^2}{9\left(a+b+c\right)-\left(a^3+b^3+c^3\right)}\)
\(\ge\frac{54}{27-2\left(a+b+c\right)+3}+\frac{9}{27-3\left(a+b+c\right)+6}=\frac{54}{24}+\frac{9}{24}=\frac{21}{8}\)
đây là toán đâu phải văn. bạn bị say rượu à
Chứng minh rằng:
\(\frac{9}{5^2}+\frac{9}{11^2}+\frac{9}{17^2}+...+\frac{9}{305^2}< \frac{3}{4} \)
\(C=\frac{11}{9}+\frac{18}{16}+\frac{27}{25}+...+\frac{1766}{1764}\)
Chứng minh rằng:\(40\frac{20}{43}< C< 40\frac{20}{21}\)
\(D=\frac{8}{9}+\frac{24}{25}+\frac{48}{49}+...+\frac{200.202}{201^2}>99,75\)
\(E=\frac{3}{4}+\frac{8}{9}+\frac{15}{16}+...+\frac{24}{2500}>48\)
Giải nhanh trong chiều này giùm mình nhé!
Tính nhanh giá trị các biểu thức sau một cách hợp lý:
A= \(\frac{27\cdot45+27\cdot45}{2+4+6+8+...+16+18}\)
B =\(\frac{135\cdot1420+45\cdot780\cdot3}{3+6+9+12+...+24+27}\)
a) Ta có : 2 + 4 + 6 + 8 +... + 16 + 18
SSH : (18 - 2) : 2 + 1 = 9(số)
Tổng : (2 + 18).9 : 2 = 90
\(A=\frac{27\cdot45+27\cdot45}{90}=\frac{27\left(45+45\right)}{90}=\frac{27\cdot90}{90}=27\)
b) Ta có : 135.1420 + 45.780.3 = 135.1420 + 135.780 = 135(1420 + 780) = 135.2200 (*)
3 + 6 + 9 + 12 + ... + 24 + 27
Số số hạng : (27 - 3) : 3 + 1 = 9(số)
Tổng : (3 + 27).9 : 2 = 135 (**)
Từ (*) và (**) suy ra
=> \(B=\frac{135\cdot2200}{135}=2200\)
a)
2 + 4 + 6 + ... + 16 + 18
Số số hạng :
( 18 - 2 ) / 2 + 1 = 9
Tổng :
( 18 + 2 ) x 9 / 2 = 90
\(A=\frac{27\cdot45+27\cdot45}{90}\)
\(=\frac{27\left(45+45\right)}{90}\)
\(=\frac{27\cdot90}{90}\)
\(=27\)
b)
3 + 6 + 9 + 12 + ... + 24 + 27
Số số hạng :
( 27 - 3 ) / 3 + 1 = 9
Tổng :
( 27 + 3 ) x 9 /2 = 135
\(B=\frac{135\cdot1420+45\cdot780\cdot3}{135}\)
\(=\frac{135\cdot1420+135\cdot780}{135}\)
\(=\frac{135\left(1420+780\right)}{135}\)
\(=\frac{135\cdot2200}{135}\)
= 2200
Bt1) Tính
a) \(\frac{2}{15}+\frac{5}{-12}-\frac{5}{18}\)
b)\(-3-\frac{-2}{9}-\frac{5}{-27}\)
c)\(\frac{7}{36}-\frac{5}{24}+\frac{3}{-18}\)
d)\(\frac{5}{4}-\frac{5}{8}+\frac{-2}{3}\)
\(a=\frac{\frac{5}{3}+\frac{5}{9}-\frac{5}{27}}{8-\frac{8}{3}+\frac{8}{9}-\frac{8}{27}}:\frac{15-\frac{15}{11}+\frac{15}{121}}{16-\frac{16}{11}+\frac{16}{121}}\)
ngày 27/2 mình sẽ giai ai giải đung sẽ dc 20 dung