Question

Daca $\frac{x}{2} = \frac{y}{9} , atunci \frac{10 x - 2y }{5x+y}$ =
Daca $\frac{3x+4y}{2x+y} = \frac{7}{3} ,atunci \frac{x}{y} =$ =
Daca $\frac{6x+4y}{5x+2y} = \frac{3}{2} , atunci  \frac{x}{y} =$ =
Daca $\frac{5x-4y}{2x-y} = \frac{7}{3} , 2x \neq y,atunci \frac{x}{y}$=

Answer 1

1)x/2=y/9=k

x=2k
y=9k

(10x-2y)/(5x+y)=  (10*2k -2*9k)/(5*2k +9k)=

=(20k-18k)/(10k+9k)=  2k/19k=  2/19

3)3(3x+4y)=7(2x+y)

9x+12y=14x +7y

9x-14x= 7y-12y

-5x= -5y

5x=5y

x=y

x/y=1

3)2(6x+4y)=3(5x+2y)

12x+8y=15x +6y

12x-15x= 6y-8y

-3x=  -2y

3x=2y

x/y= 2/3

4)3(5x-4y)=7(2x-y)

15x -12y =14x -7y

15x-14x = -7y +12y

x= 5y

x/y= 5