9/25.x+3/5.(9/25+18)+9/25.x+18=x
Tìm x
\(\frac{9}{25}x+\frac{3}{5}\left(\frac{9}{25}x+18\right)+\frac{9}{25}x+18=x\)
Ta có \(\frac{9}{25}x+\frac{3}{5}.\frac{9}{25}x+\frac{3}{5}.18+\frac{9}{25}x+18=x\)
=> \(\frac{9}{25}x\left(1+\frac{3}{5}+1\right)+18\left(\frac{3}{5}+1\right)=x\)
=> \(\frac{117}{125}x+28,8=x\)
=> \(x-\frac{117}{125}x=28,8\)
=> \(\frac{8}{125}x=28,8\)
=> x = 450
Vậy x = 450
\(\frac{9}{25}x+\frac{3}{5}.\frac{9}{25}x+\frac{3}{5}.18+\frac{9}{25}x+18=x\)
\(x\left(\frac{9}{25}+\frac{9}{25}+\frac{9}{25}\right).\frac{3}{5}+\frac{3}{5}.18+18=x\)
\(x.\frac{3}{5}\left(\frac{27}{25}+18\right)+18=x\)
\(x.\frac{3}{5}\left(\frac{27}{25}+\frac{450}{25}\right)+18=x\)
\(x.\frac{3}{5}.\frac{477}{25}+18=x\)
\(x.\frac{1431}{125}+\frac{2250}{125}=x\)
\(x.\frac{3681}{125}=x\)
vậy chac tui làm sai rồi
1/9 x 18/5 và 3/25 : 9/5
\(\dfrac{1}{9}\times\dfrac{18}{5}=\dfrac{2}{5}\)
\(\dfrac{3}{25}:\dfrac{9}{5}=\dfrac{3}{25}\times\dfrac{5}{9}=\dfrac{1}{15}\)
a, = 18/45 = 2/5
b, = 3/25 x 5/9 = 15/225 = 1/15
Cho Elip (E): \(\frac{x^2}{25}+\frac{y^2}{9}=1\) và đường thẳng (d): x= - 4 cắt (E) tại hai điểm M,N. Khi đó: a. MN=9/5 b. MN=9/25 c. MN=18/5 d. MN=18/25
Thay \(x=-4\) vào pt elip ta được:
\(\frac{y^2}{9}=1-\frac{16}{25}=\frac{9}{25}\Rightarrow\left[{}\begin{matrix}y=\frac{9}{5}\\y=-\frac{9}{5}\end{matrix}\right.\)
\(\Rightarrow MN=2.\frac{9}{5}=\frac{18}{5}\)
tính : 18/51 x 34/9 x 17/18 ; 21/32 x 4/7 x 25 x 4/5
a: \(=\dfrac{18}{51}\cdot\dfrac{34}{9}\cdot\dfrac{17}{18}=\dfrac{17}{51}\cdot\dfrac{34}{9}=\dfrac{1}{3}\cdot\dfrac{34}{9}=\dfrac{34}{27}\)
b: \(=\dfrac{21}{32}\cdot\dfrac{4}{7}\cdot25\cdot\dfrac{4}{5}=\dfrac{21}{7}\cdot\dfrac{4}{32}\cdot20=60\cdot\dfrac{1}{8}=\dfrac{15}{2}\)
3^x+3^x+4=9^25+27^18
\(\Leftrightarrow3^x\cdot82=3^{50}+3^{54}\)
hay x=50
Tính nhanh
9 x 9 + 25 x 9 + 33 +18
9x9+25x9+33+18
=3x27+75x3+3x11+3x6
=3x﴾27+75+11+6﴿
=3x139
=417
ủng hộ nha e nguyen hai Yen
So sánh a, (-12) x 1125 x (-9) x(-5).3 với 0
b, 21.(-25).(-6).(-3).18.(-2022) với 0\(a,\left(-12\right).1125.\left(-9\right).\left(-5\right).3=-1822500< 0\)
\(b,21.\left(-25\right).\left(-6\right).\left(-3\right).18.\left(-2022\right)=343942200>0\)
Tìm số nguyên x bt
9-25=(7-x)-(25+7) 10+2.|x|=2.(32-1)
-6x=18. 35-3.|x|=5.(23-4)
a: 9-25=7-x-(25+7)
=>7-x-25-7=-16
=>-x-25=-16
=>x+25=16
hay x=-9
b: \(10+2\left|x\right|=2\cdot\left(3^2-1\right)\)
\(\Leftrightarrow2\left|x\right|=2\cdot8-10=6\)
=>x=3 hoặc x=-3
c: -6x=18
nên x=18:(-6)=-3
b) 9/5.x=18/25
e)x-20%.x=2,5
\(b)\frac{9}{5}.x=\frac{18}{25}\)
\(\Rightarrow x=\frac{18}{25}\div\frac{9}{5}=\frac{18}{25}.\frac{5}{9}\)
\(\Rightarrow x=\frac{2}{5}\)
\(e)x-20\%.x=2,5\)
\(\Rightarrow x.\left(1-\frac{1}{5}\right)=\frac{5}{2}\)
\(\Rightarrow x.\frac{4}{5}=\frac{5}{2}\)
\(\Rightarrow x=\frac{5}{2}\div\frac{4}{5}=\frac{25}{8}\)
b) \(\frac{9}{5}\). x = \(\frac{18}{25}\)
x = \(\frac{18}{25}\): \(\frac{9}{5}\)
x = \(\frac{2}{5}\)
e) x - 20% . x = 2,5
1 . x - \(\frac{1}{5}\). x = \(\frac{5}{2}\)
x . ( 1- \(\frac{1}{5}\)) = \(\frac{5}{2}\)
x . \(\frac{4}{5}\)= \(\frac{5}{2}\)
x = \(\frac{5}{2}\): \(\frac{4}{5}\)
x = \(\frac{25}{8}\)
=^_^=
h mình nha