Question

 Tìm x : 

    a,  x/13 = 35/91                                                        c,   x + x : 5 * 7.5 + x : 2 * 9 = 315

    b, 9 + x / 13 - x = 5 / 6                                              d,  2/3 * x + 1/2 = 9/10 - 1/5

Answer 1

a, \(\frac{x}{13}=\frac{35}{91}\)
=> x = 35.13 : 91 
=> x = 5 
b ) \(\frac{x}{13}-x=\frac{5}{6}-9=\frac{-49}{6}\)
=> \(\frac{x-13x}{13}=\frac{-49}{6}\)
=> -12x . 6 = -49 . 13 
=> -12x . 6 = - 637 
=> -12x = -637 : 6 =\(\frac{-637}{6}\)
=> x = \(\frac{-637}{6}:-12=\frac{-637}{72}\)
c, \(x+\frac{x}{5}.7,5+\frac{x}{2}.9=315\)
\(x+\frac{7,5x}{5}+\frac{9x}{2}=315\)
\(x+\frac{60x}{10}=315\)
\(x+6x=315\)
\(7x=315\Rightarrow x=315:7=45\)
d, \(\frac{2}{3}.x+\frac{1}{2}=\frac{9}{10}-\frac{1}{5}\)
\(\frac{2}{3}x+\frac{1}{2}=\frac{7}{10}\)
\(\frac{2}{3}x=\frac{7}{10}-\frac{1}{2}=\frac{1}{5}\)
\(x=\frac{1}{5}:\frac{2}{3}=\frac{3}{10}\)

Answer 2

mình mới đọc câu a thôi nhé

x=5

Answer 3

a)x=5 nha ban

Answer 4

mk chiu ban a

Answer 5

A, x=5