Răspuns:
Explicație pas cu pas:
(x + 2)/x = 9/7
7(x + 2) = 9x
7x + 14 = 9x
9x - 7x = 14
2x = 14
x = 14 : 2 = 7
______________
x/(x + 1) = 2/13
13x = 2(x + 1)
13x = 2x + 2
13x - 2x = 2
11x = 2
x = 2/11
_____________
x/5 = (x + 2)/25
25x = 5(x + 2)
25x = 5x + 10
25x - 5x = 10
20x = 10
x = 10/20 = 1/2
(x+2)/x=9/7
7(x+2)=9x
7x+14=9x
7x-9x=-14
-2x=-14
x=7
x/x+1=2/13
13x=2(x+1)
13x=2x+2
13x-2x=2
11x=2
x=2/11
x/5=(x+2)/25
25x=5x+10
25x-5x=10
20x=10
x=1/2=0,5
