a)2 supra3 =6 supra x ;
2/3=6/x
2x=6*3
2x=18
x=18:2
x=9
;b)x supra 1,2 =10 supra 3
x/1.2=10/3
3x=1.2*10
3x=12
x=12:3
x=4
3,5 supra x =7 supra 4
3.5/x=7/4
7x=3.5*4
7x=14
x=2
2,52 supra 1,14 =x supra 1,9
2.52/1.14=x/1.9
1,14x=1.9*2.52
1.14x=4.788
x=4.2
x+1 supra 4 = 5 supra2
(x+1)/4=5/2
2(x+2)=20
2x+4=20
2x=16
x=8