Question

Dacă x/y =4/9 diferit de 0 , atunci 3x+2y/5x+y = ...... b) dacă x/y=3/5 , y diferit de 0 , atunci 4x+6y/x+y = .... , c) dacă x/4=y/7 , atunci 9x-2y / x+3y .... d) dacă x/2=y/9 , atunci 10x-2y / 5x+ y=...

Answer 1

x/y = 4/9   
a) y = 9x/4 = 2,25x    (3x+2y)/(5x +y) = (3x +5,5x)/(5x + 2,25x) = 8,5x/7,25x =
= 17/14,5 = 170/145 = 34/29
b) x/y = 3/5    (x+y)/y = 8/5    x+y = 8y/5 = 1,6y      x = 0,6y
(4x +6y)/(x +y) = (2,4y + 6y)/1,6y = 8,4y/1,6y = 5,25
c)  x/4 = y/7    y = 7x/4 = 1,75x
(9x-2y)/(x +3y) = (9x - 3,5x)/(x+5,25x) = 5,5x/6,25x = 0,88
d)  x/2 = y/9    y = 9x/2 = 4,5x
(10x - 2y)/(5x+y) = (10x - 9x)/(5x+ 4,5x) = x/9,5x = 1/9,5 = 10/95 = 2/19