\(\frac{a}{27}\)=\(\frac{-5}{9}\)=\(\frac{-45}{b}\)
Tìm a, b biết: \(\frac{a}{27}=\frac{-5}{9}=\frac{-45}{b}\)
Vì \(\frac{a}{27}=\frac{-5}{9}\)=> Phân số \(\frac{-5}{9}\)bị rút gọn 3 lần . Vậy ta có phân số \(\frac{-15}{27}\)=> a = 15
Vì \(\frac{-5}{9}=\frac{-45}{b}\)=> Phân số \(\frac{-5}{9}\)đã nhân cả tử và mẫu số với 9 => Ta có phân số \(\frac{-45}{81}\)=> b = 81
=> a = 15 , b = 81
Tìm a , b biết
\(\frac{a}{27}=\frac{-5}{9}=\frac{-45}{b}\)
\(a=-\frac{5}{9}.27=-15\)
\(b=-45:\left(-\frac{5}{9}\right)=45.\frac{9}{5}=81\)
Đáp số: a=-15; b=81
Bài làm
Ta có: \(\frac{a}{27}=-\frac{5}{9}=-\frac{45}{b}\)
=> a = ( -5 ) . 27 : 9 = - 15
=> b = -45 . 9 : ( - 5 ) = 81
Vậy a = -15; b = 81
Tìm a, b biết:
\(\frac{a}{27}=\frac{-5}{9}=\frac{-45}{b}\)
\(\frac{a}{27}=\frac{-5}{9}=\frac{-45}{b}\)
Vì \(\frac{a}{27}=\frac{-5}{9}\Rightarrow9.a=\left(-5\right).27=-135\Rightarrow a=\frac{-135}{9}=-15\)
Vì \(\frac{-5}{9}=\frac{-45}{b}\Rightarrow-5.b=\left(-45\right).9=-405\Rightarrow b=\frac{-405}{-5}=\frac{405}{5}=81\)
Vậy a=-15;b=81
Vì \(\frac{a}{27}=\frac{-5}{9}\Rightarrow\frac{a}{27}=\frac{\left(-5\right).3}{9.3}\)
\(\Rightarrow\frac{a}{27}=\frac{-15}{27}\Rightarrow a=-15\)
Lại có: \(\frac{-5}{9}=\frac{-45}{b}\Rightarrow\frac{\left(-5\right).9}{9.9}=\frac{-45}{b}\)
\(\Rightarrow\frac{-45}{81}=\frac{-45}{b}\Rightarrow b=81\)
Vậy a=-15;b=81
Tìm a,b biết :
\(\frac{a}{27}=\frac{-5}{9}=\frac{-45}{b}\)
Làm giúp mình nhé !!!
Ai nhanh sẽ được tik ! :D
Giải\(\frac{a}{27}=-\frac{5}{9}\)
=> 9.a=-5.27
=>9a= -135
=> a = -135 : 9
=> a = 15
Giải \(\frac{-5}{9}=-\frac{45}{b}\)
=> -5b = -45 x 9
=> =5b = - 405
=> b = - 405 : ( - 5 )
=> b = 81
Vậy a = 15 ; b = 81
a/27 = -5/9
suy ra 9a=-5*27 suy ra a=-15
Tương tự b=-45*9/-5=81
1) Tinh :a) \(\frac{3^6.45^4-15^{13}.5^{-9}}{27^4.25^3+45^6}-\frac{50}{7}.\frac{\sqrt{0,49}}{25}\)
b) Tim x , biet: \(|2x-\frac{1}{5}|\left(-\frac{1}{5}\right)^5=\left(-\frac{1}{5}\right)^7\)
Bài 1: Tìm x biết: a, |2x+5|-|x+3|=0
Bài 2: Rút gọn:
a,\(\frac{3^6+45^4-15^3.4^5}{27^4.25^3+45^6}\)
b,\(\frac{\left(\frac{2}{5}\right)^7.5^7+\left(\frac{16}{3}\right)^3:\left(\frac{4}{9}\right)^3}{2^7.5^2+512}\)
2a) \(\frac{3^6+45^4-15^3.4^5}{27^4.25^3+45^6}\)
= \(\frac{3^6+\left(3^2.5\right)^4-\left(3.5\right)^3.\left(2^2\right)^5}{\left(3^3\right)^4.\left(5^2\right)^3+\left(3^2.5\right)^6}\)
= \(\frac{3^6+3^8.5^4-3^3.5^3.4^{10}}{3^{12}.5^6-3^{12}.5^6}=\frac{3^3.\left(3^3+3^5.5^4-5^3.4^{10}\right)}{0}\)(xem lại đề)
b) \(\frac{\left(\frac{2}{5}\right)^7.5^7+\left(\frac{16}{3}\right)^3:\left(\frac{4}{9}\right)^3}{2^7.5^2+512}\)
= \(\frac{\left(\frac{2}{5}.5\right)^7+\left(\frac{16}{3}:\frac{4}{9}\right)^3}{2^7.5^2+2^9}\)
= \(\frac{2^7+12^3}{2^7\left(5^2+2^2\right)}\)
= \(\frac{2^7+\left(2^2.3\right)^3}{2^7.29}\)
= \(\frac{2^7+2^6.3^3}{2^7.29}\)
= \(\frac{2^6\left(1+27\right)}{2^7.29}=\frac{28}{2.29}=\frac{14}{29}\)
mk xin lỗi bn nhé...mk vt nhầm đề...mk vt lại nha:
2a,\(\frac{3^6+45^4-15^3.9^5}{27^4.25^3+45^6}\)
a) A=\(\left(\frac{-5}{11}\right).\frac{7}{15}.\left(\frac{11}{-5}\right).\left(-30\right)\)
b) B=\(\left(-\frac{1}{6}\right).\left(\frac{-15}{19}\right).\left(\frac{38}{45}\right)\)
c) C= \(\left(\frac{-5}{9}\right).\frac{3}{11}+\left(\frac{-13}{18}\right).\frac{3}{11}\)
d) D= \(\left(2\frac{2}{15}.\frac{9}{17}.\frac{3}{32}\right):\left(\frac{-3}{27}\right)\)
\(\frac{2}{3}+\frac{6}{5}+\frac{9}{10}+\frac{14}{15}+\frac{20}{21}+\frac{27}{28}+\frac{35}{36}+\frac{44}{45}+\frac{44}{55}\)
a)A=\(\frac{16^3.3^{10}+120.6^9}{4^6.3^{12}+6^{11}}\) b)B=\(\frac{45}{19}-\left(\frac{1}{2}\left(\frac{1}{3}+\left(\frac{1}{4}\right)^{-1}\right)^-\right)^{-1}\) c)C=\(\frac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^{10}.6^{19}-7.2^{29}.27^6}\)
d)D=\(\frac{2^{21}.3^5-4^6.81}{\left(2^2.3\right)^6+8^4.3^5}\) e) E=\(\left(6^9.2^{10}+12^{10}\right):\left(2^{19}.27^3+15.4^9.9^4\right)\)
f) F=\(\frac{3^6.45^4-15^{13}.5^{-9}}{27^4.24^3+45^6}\) g)G=\(\frac{\left(\frac{2}{5}\right)^7.5^7+\left(\frac{9}{4}\right)^3:\left(\frac{3}{16}\right)^3}{2^7.5^2+512}\) h)H=\(x+\frac{0,2-0,375+\frac{5}{11}}{-0,3+\frac{9}{16}-\frac{15}{22}}\)với x=-1/3
ai nhanh nhất mà trả lời dúng mik tặng 3 k