Question

Tìm x, biết:
a. \(\frac{x}{13}=\frac{35}{91}\) 
b.\(\frac{9+x}{13-x}=\frac{5}{6}\)
c. \(x\) + \(X\)  : 5 x 7,5 + \(x\) : 2 x 9 = 315

Answer 1

a) Ta có : \(\frac{35}{91}\)= \(\frac{5}{13}=\frac{x}{13}\Rightarrow x=5\)

 

Answer 2

b, ta có

<=>6 (9+x)=5 (13-x)

<=>54+6x=65-5x

<=>6x+5x=65-54

<=>11x=11

<=>x=1

Answer 3

a)35/91=x/13.Vì 91:13=7,suy ra x=35:7=5.

Answer 4

ta có 91:13=7=> x nhân 7=35 x=35:7x=5