\(x^2=900\Leftrightarrow x^2=30^2\Rightarrow x=30\)
Chọn A
\(x^2=900\Leftrightarrow x^2=30^2\Rightarrow x=30\)
Chọn A
GIÚP MÌNH VỚI
a, x - \(\dfrac{5}{7}\)=\(\dfrac{19}{21}\)
b,\(\dfrac{5}{3}\)-I x - \(\dfrac{1}{5}\)I = \(\dfrac{1}{3}\)
c, (x - \(\dfrac{2}{5}\)) = \(\dfrac{1}{4}\)
d, 5\(\sqrt{x}\) - 30 = 15
nếu \(\dfrac{5}{x}\)= \(\dfrac{2}{3}\)thì x bằng:
A.\(\dfrac{2}{3}\) B.\(\dfrac{15}{2}\) C.\(\dfrac{3}{2}\) D.\(\dfrac{2}{15}\)
Tìm x:
a) \(\dfrac{x-1}{-15}=\dfrac{-60}{x-1}\)
b) \(\left|x+\dfrac{4}{5}\right|+\dfrac{3}{5}=\dfrac{2}{5}\)
c) \(\left(x-\dfrac{1}{2}\right)^3=\dfrac{1}{27}\)
Tìm x, y , thuộc Q biết :
a , \(\dfrac{x}{15}=\) \(\dfrac{-2}{6}\) b, \(\dfrac{3}{x}\) \(=\dfrac{1,8}{2}\)
c, \(\dfrac{x-3}{x+2}\) \(=\dfrac{2}{7}\) d, \(\dfrac{x+1}{3}=\dfrac{x-6}{8}\)
e,\(\dfrac{2-x}{5}=\dfrac{x+4}{3}\) g,\(\dfrac{2x+1}{-3}=\dfrac{1-x}{2}\)
2, Cho 4 số \(x=\dfrac{3}{-8}\) ; \(y=\dfrac{-5}{12}\) ; \(Z=\dfrac{60}{160}\) \(T=-0,6\)
a, So sánh x và y ; Z và T ; x và Z
b, tính x + t và y - z
c, Tính y + z + t
d, Tìm số lớn nhất và số nhỏ nhất trong 4 số
\(\dfrac{40}{x-30}=\dfrac{20}{y-15}=\dfrac{28}{z-21}vàx.y.z=22400\)
1, Tìm x ∈ Z biết
a, \(\dfrac{x-4}{15}\)=\(\dfrac{5}{3}\)
b, \(\dfrac{x}{4}\)=\(\dfrac{18}{x+1}\)
c,2x+3 ⋮ x+4
\sqrt{1} \(\dfrac{help}{me}\)
tìm x
a/\(\dfrac{x}{2}=\dfrac{32}{x}\)
b/\(\dfrac{5}{25}=5\)
c/\(\dfrac{30^x}{27^x}=27\)
d/5x . 10x=2500
Tìm x:
a) \(\dfrac{11}{12}\) - (\(\dfrac{2}{5}\) + \(\dfrac{3}{4}\)x) \(\dfrac{2}{3}\)
b) \(\dfrac{-2}{5}\) + \(\dfrac{5}{3}\) . (\(\dfrac{3}{2}\) - \(\dfrac{4}{15}\)x) = \(\dfrac{-7}{6}\)
c) \(\dfrac{1}{2}\) + \(\dfrac{3}{4}\)x = \(\dfrac{1}{4}\)