Question

Tìm x biết :

a) \(\left[\left(6\frac{3}{5}-3\frac{3}{14}\right).2,5\right]:\left(21-1,25\right)=x:5\frac{5}{6}\)

b) \(\left(4-\frac{3}{4}\right):\left(2\frac{1}{3}-1\frac{1}{9}\right)=31x:\left(45\frac{10}{63}-44\frac{25}{84}\right)\)

c) \(\frac{x-1}{x+5}=\frac{6}{7}\)

d) \(\frac{x^2}{6}=\frac{24}{25}\)

e) \(\frac{x-2}{x-1}=\frac{x+4}{x+7}\)

giúp mình nhé 

Answer 1

e)

=> (x-2) . (x+7) = ( x-1 ) . ( x +4)

=> x² +7x - 2x -14 = x² - x + 4x - 4

x² + 5x - 14 = x² + 3x - 4

=> 5x - 14  = 3x - 4

=> 5x  - 3x = 14-4

=> 2x         = 10 => x = 10 : 2 => x = 5

c)

=>( x-1) . 7 = ( x + 5 ) . 6

=> 7x - 7 = 6x + 30

=> 7x - 6x=  30 + 7

=> x         = 37

Answer 2

a,x=\(\frac{5}{2}\)

b,x=\(\frac{13}{176}\)

c,x=37

d, x=\(\frac{12}{5}\)

e, x=5